In both of those epidemics, the primary focal point was decisively suppressed. Then, in both previous incidents, the further spread of the virus was stopped in more than 25 countries using the first line of defense, ie, identifying all those infected, tracing their contacts, and isolating them ,2.th of February, the first estimates of death rates were published, suggesting that they were much lower than those of SARS and MERS [By the end of February 2020, it was already clear that COVID-19 would also be successfully suppressed in its primary focal point − Wuhan. Then, it was also stopped using the first line of defense in another thirty Chinese provinces, all of which are very large population-wise. The surrounding countries in Asia, ie, Japan, Taiwan, South Korea, and Singapore, seemed to control the virus successfully. Then, on the 24and MERS .Furthermore, epidemiologists expected that there would likely be many asymptomatic cases and mild forms of the new disease. Minding the size of Wuhan’s population where those cases would have been unaccounted for, it was still quite possible that the net effect of this virus may not be much worse than of harsh influenza for which no vaccine was available. This is why experts were rather relaxed at this point. At that time, it seemed to them that the scenario of the SARS and MERS was repeating and that the illness itself was not too dangerous. It was reasonable to expect that the epidemic could soon be stopped.th of March [th of February to the 3rd of March [As a result, the World Health Organisation delayed the declaration of a pandemic until the 11of March . Global of March . But forWhen the crisis caused by the new coronavirus from Asia began to spread to Europe and the Americas through air travel, the virus managed to penetrate beyond the front lines of defense in highly developed Western countries. I described the cascade of events that led to the free spread of the virus in Europe in another article . At thatWith the first option, the reaction was to be instinctive. Nations would be pulled into strict quarantines to prevent the virus from spreading rapidly through exponential growth and the move would protect human lives. During the quarantine, scientists would need to learn more about the virus and assess the level of danger and the effectiveness of different containment measures. But it was clear to everyone that quarantine was unsustainable. It would be enormously damaging to society if enacted without a feasible exit strategy. Namely, after several weeks of quarantine, many people would be left without means for the further purchase of basic groceries. They would also start losing their jobs.Therefore, the “large quarantine” strategy was undermined by its unacceptability to many people after several weeks. It was going to be increasingly difficult to expect that people would adhere to the level of strict social distancing required to keep the epidemic under control. This would be especially true knowing that the risk of dying from COVID-19 was not particularly high. Then, if many people started ignoring anti-epidemic measures and went back to their pre-COVID-19 lifestyles, many would get infected soon thereafter. Countries would then need to start a new cycle of isolation because their health systems would be unable to handle large numbers of infected people with a severe form of the disease.Another option for the rulers of western countries was to let the virus spread and infect a significant portion of the population. Under such a scenario, it was hoped that many citizens would gain more permanent immunity by overcoming the disease. As a result, the virus would have fewer people to infect. Its spread would then slow down. However, since neither drugs nor vaccines against the novel coronavirus were available, this approach would inevitably lead to many deaths − especially among the elderly and those with pre-existing diseases. Still, life as we knew it would continue and the economy would be saved from a major disruption.Yet, the “free spread” strategy was also undermined by the predicted human behavior. Namely, even if the plan were carefully explained to the population and it gained support from a large majority, the rapid increase in the death toll, especially in comparison to quarantined countries, would soon become unacceptable to most of the population. In this scenario, too, it would be increasingly difficult to maintain the responsibility and discipline required to preserve the economy. When people realize that they might end up in intensive care units themselves, many would find excuses to take to their homes and stay isolated for a long time. Then, many businesses would collapse and the number of unemployed people would increase sharply, despite the fact that this plan initially sought to save jobs.In conclusion, in both possible approaches to this crisis, the behavior of the population, which will increasingly decline to participate in either plan, would eventually undermine the implementation. In the former case, they would resent the plan for economic reasons; in the latter, for fear of their lives and the lives of their families.This was quite clear to the leaders of the western countries, which is why some were keen to seek their own, third approach. But the approach that would be even worse than these two extreme scenarios was to initially confront the epidemic with one strategy and then change it after a few weeks and move on to the alternative approach. Consistent adherence to the first solution would at least save the maximum number of human lives, albeit only temporarily, but it would significantly harm the economy. Conversely, consistent adherence to the alternative solution would preserve the economy and lifestyle, at least in theory, but with significant loss of life that was extremely difficult to estimate at the time. But, if the leaders picked one initially, and after a few weeks they had to change their minds and choose the other, then both the economy would suffer and the casualties would be quite large. So, governments were facing two seemingly very bad solutions, and the alternation between them would be even worse.To make the choice even harder than it had seemed already, it had to be made under major uncertainties over nearly all key parameters. The leaders could not be entirely sure what was the case-fatality rate (CFR) of the novel coronavirus SARS-CoV-2 − or its infection-fatality rate (IFR), if there were many asymptomatic cases of infection, which still needed to be established. They did not know the spread rate, either, ie, the R0 parameter. They did know that the growth of cases would be exponential. There was also a major uncertainty over the extent of risk by age and sex. This was mainly because the data from China lumped many age groups together and it was uncertain at the time if COVID-19 may be dangerous for younger people, too .Furthermore, no-one could tell with any certainty if the existing drugs would work against COVID-19, or if they could be repurposed to help save lives. It was not known how long would it take to develop a new vaccine, either. Importantly, no-one could be sure if the acquired immunity would be persistent, or if it would diminish soon. Finally, there was considerable uncertainty whether the virus may be seasonal and simply disappear towards the end of May. These were terrible circumstances to make any important decisions. There were many opportunities to make serious mistakes.Large quarantines seemed an appropriate temporary solution until scientists could understand how many people become infected without developing significant symptoms. Without that information, it was not possible to predict the effects of the virus on population-level mortality. Although most epidemiologists believed that those effects should be considerably smaller than they appeared from simply dividing the deaths by the confirmed infections, there was no firm evidence for this. The virus was new, so no assumptions were allowed, as they could be very costly and lead to many casualties.In addition to uncertainties over the “death rate” of the virus, the other uncertainty that worried many epidemiologists was that it “spread rate” remained unknown. If very high, it could make the indirect effects of the new virus worse than the direct ones. It could generate many severe cases that could not be helped due to a health system overload. The consequent overload of the health system would indirectly lead to further casualties due to the inadequate treatment of all other diseases. For this reason, it was extremely difficult to estimate the effects of the free spread of the virus and the number of likely casualties. At the same time, the negative effects of quarantines on human mental health and well-being were also expected. The consequences of economic hardship for many people over the years to come were also very difficult to assess.The strategy of allowing the free spread of the virus was also very dangerous because it was impossible to predict the ways in which the virus could mutate after infecting so many human carriers. Some new strains could, in principle, become more severe than the current one. A further danger of this strategy was that even low levels of risk for young people would translate into very large numbers if millions were infected. Relatively young victims would surely become a central focus of reporting on the epidemic and undermine any support that this strategy may have enjoyed beforehand.Another problem with the “free spread” strategy was that if it succeeded to some extent, even with considerable casualties, the virus would still continue to mutate. In its new circle around the world during the next season, COVID-19 would likely shorten many lives again. The immunity acquired during a previous season may no longer protect − as is the case with the flu. This would make many victims of the “free spread” strategy during the first wave seem futile as any “herd immunity” that was acquired then would be lost. Few leaders would consider accepting responsibility for such outcomes in view of so many uncertainties.Most leaders agreed to quickly and decisively close off the pathways of further spread to the virus. This avoided the unbearable situation of having too many infected people requiring hospitalization too quickly. It protected the health system from collapse and saved many human lives. After that, there would be a very wide range of further options.The author Tomas Pueyo outlined a sensible strategy of response in Medium.com . It becaFurthermore, “the Hammer” phase would buy more time for key decisions. During the lockdown we could all learn more about the virus, educate the population, progress some key research, strengthen the capacity to deal with the virus after the lockdown, and learn from others who were ahead in time .This was quite well understood from late March, once it became apparent that many countries were taking proactive measures and implementing lockdowns. The assessment of each country’s performance in dealing with the coronavirus crisis would then be based on the following five questions:How effectively did the “first line of defense” manage to prevent the free spread of coronavirus among the population, and for how long?Once the “first line of defense” was broken and an exponential spread of the virus began, how quickly and decisively was a lockdown activated?How closely did the population adhere to lockdown measures? This step was one where countries would depend on the relationship between the leaders and their population, trust of people in their government’s ability to deal with the crisis, people’s discipline and adherence to measures.How fast and active was the state to mobilize its capacities and human resources, as well as creative and innovative solutions, to develop a concrete plan for quarantining and plans for later coexistence with coronavirus as quickly as possible? This needed to include empowerment of technological capabilities and human resources for virus testing, innovative ideas on social removal measures, effective virus control measures, the use of technologies to understand human contacts and the spread of viruses, etc.How effectively, after quarantine, has the state enabled its population to move into relatively normal life and preserve their economy from collapse, with permanent control over the spread of the virus?We have seen four different types of strategies. I will rank them from the least to the most interventionist. The first type of response was to allow the virus to spread among the population. The idea was to partly expose the population to the virus. If we could “immunize” ourselves while preserving reasonably normal life, there was a hope that economic activities would not be too disrupted. Sweden, the United Kingdom, the United States, the Netherlands, and, to a certain extent, Germany, led the way in this regard.The second type of response was to rely on a strong “first line of defense”. In some countries, this approach was facilitated by a high level of economic development, modern technologies, a strong capacity to test people for the presence of the virus, as well as the rapid monitoring and isolation of their contacts with modern technologies. The best examples of this approach were South Korea, Taiwan, Singapore, Japan, United Arab Emirates, Qatar, and Iceland.The vast majority of countries found themselves in the third group. After a short period in which they tried to stop the virus through their “first lines of defense”, they all had to move to a back-up plan. This involved them closing the borders, schools and banning public gatherings. They were then quarantined for several weeks to prevent the contagion and significantly reduce the daily number of new cases of coronavirus infection. During the quarantine period, exit strategies were being considered on how to co-exist with the virus until effective drugs or vaccines could be made.Finally, the fourth example involves countries that started with their quarantine measures early enough, or implemented them so intensively, that they practically eliminated the virus from within their respective borders. China was an early example of this, but thanks to the success of its measures so far, there was also hope for New Zealand, Vietnam, Montenegro, and a handful of other countries.It turned out that all four initial approaches, after enough time, were more or less forced to switch to the same strategy: they needed to apply either a national-level or a localized social distancing of varying degrees of stringency. Although many have sought to preserve their normal lifestyle and indeed their economy for as long as possible, the United States and the United Kingdom now have an enormous number of infected people. The United States is sure to have the highest absolute death toll after the first wave of the epidemic.The United Kingdom will also have a very large number of coronavirus casualties, which may end up even worse than that USA when expressed per capita. Germany is managing to keep the death toll quite low compared to the number of infected people. Germans owe this to the spread of the infection mainly among younger age groups, as well as excellent epidemic prevention measures in hospitals and retirement homes and their strong intensive care facilities. The Netherlands, like the aforementioned countries, has since moved to stricter quarantine measures .Only Sweden continues to rely on the discipline of its citizens and somewhat less stringent social distancing measures to try to keep the virus at bay. They are trying to avoid a complete lockdown, although some social distancing measures are in place and the population has largely moved indoors. Currently, the death toll is significantly higher in Sweden than in their neighboring countries, but it is obviously not yet considered to be large enough to trigger a complete lockdown . I writeUnfortunately, we are increasingly seeing that even those nations that have sought to defend themselves against the COVID-19 epidemic by maintaining a “first line of defense” are slowly yielding. For ten weeks, they have been fighting hard to prevent the virus from spreading freely among the population. They achieved this through mass testing and the rapid isolation of patients and their personal contacts. Although it seemed for a long time that these countries would succeed in this approach, Singapore recorded as many as 623 new cases on the 17th of April, mainly among their migrant workers, and a real epidemic is now gathering pace there .The same is true for Japan with 556 new cases of infection, Qatar with 560 and the United Arab Emirates with 477 newly infected people in just one single day. All four of these countries have now substantially tightened their respective social distancing measures .Only South Korea and Taiwan seem to still be succeeding in the “first line of defense” approach. There, the number of newly infected people is still successfully maintained at a low figure without imposing lockdowns. They succeed in this with a massive amount of population testing and the use of rather intrusive methods of monitoring personal contacts through GPS and mobile telecommunications. These two countries have learned from the SARS experience and they were excellently prepared for this one. They remain the only ones to still be resisting it with their “first line of defense” alone, although Iceland and Cuba have also achieved this to a significant degree ,14.Iceland and New Zealand have been able to reap the benefits of their favorable geographical locations. Owing to that, they could, much like China, eliminate the novel coronavirus from their territory. However, the most successful reaction in the world, in general, was probably that of Vietnam, another country which recalls the SARS pandemic very well. Vietnam recorded 63 cases and 5 deaths of SARS back at that time. Today, that country, with a population of almost 100 million, still did not record a single victim of COVID-19 . AdmitteHowever, a new challenge for all countries that have managed to completely suppress the spread of the virus at an early stage is that, in the next phase, every person entering the country will be a new potential source of the epidemic spread. Therefore, they will only be able to relax their measures when medicines or vaccines are developed. Until then, they will continue to depend on the tight control of their borders and 2-week self-isolation for everyone who enters.A more general conclusion is that nearly all countries across the world were forced, at least over a period of time, to abandon their initial strategies and move to stricter lockdown measures. There are only a few rare exceptions. Elsewhere, the rapid spread of the new coronavirus simply could not be averted using any other means.st of May, 2020), we still do not know with sufficient precision the answer to either of those questions. Therefore, all countries are making their own decisions in the face of this unexpected situation, which is entirely new to us and still quite unpredictable.To answer this question clearly enough, we should first have sufficient certainty what the real threat of the virus could be at the level of the entire population. We should also fully understand the economic, health, and any other indirect threats from ‘’halting the world” over several weeks. Unfortunately, at the time of writing this article , in its latest estimates, predicted that the number of people who may die from COVID-19 in most countries by autumn 2020 is comparable to severe flu, assuming that anti/epidemic measures against COVID-19 have taken place . The peaAnother reason why the comparisons with more severe flu from the beginning of the pandemic appeared to have been wrong was the events in Italy. The way they were portrayed by the media at the time seemed entirely incompatible with public understanding of the flu. However, Italy presented a version of the epidemic spread of COVID-19 where the epidemiological response was largely missing, and the virus spread freely and quickly among many of Italy’s very old people. The situation there was dominated by epidemics in retirement homes and hospital wards. As a result, the number of infected, and thus of the dead, rose very sharply. The mean age of those deceased was more than 80 years, but this was not apparent from media reports. This is why the “death rate” seemed to exceed 5% .This sounded very scary indeed at the time. However, it was not clear at all from the media reports that the virus was spreading rapidly among the population who were most likely to die, which would provide a correct perspective for those figures. Almost 90% of the deaths were in people who were over 70 years old. In the vast majority of those cases, they were already suffering from one or more serious illnesses. This important information was not clearly communicated. The media only reported on the huge number of deaths, and occasionally on isolated younger patients or terrifying individual testimonies .In their early addresses at the end of February 2020, many epidemiologists suspected that the victims would be predominantly elderly people. For most COVID-19 victims, their lives would be shortened by several years, which would be spent at an older age and undergoing treatment for pre-existing illnesses. There is also another important detail that epidemiologists also emphasized in their first addresses, but due to the then lower level of understanding of pandemics, only a few people noticed or understood that point. In the beginning, journalists and the general public were primarily concerned with the question of the “death rate”, and whether the virus could mutate to increase it and kill more people among those infected. At first glance, that does seem to be the most important question. But many epidemiologists kept saying that the virus could also mutate in another way, to start spreading more rapidly. I personally stated this publicly as early as on the 27th of February, saying that I was actually more worried about that possibility.The problem of the rapid spread of the virus, measured through R0 parameter, seemed far less important to the public at the time than the “death rate”. But it presents a greater challenge to epidemiologists when they are planning measures to contain the epidemic than the “death rate” itself does. From an epidemiologist’s perspective, even a very high “death rate” at which we can still monitor and isolate all infected persons and their contacts is easier to deal with than a low “death rate” with a very rapid spread. The best example is this new coronavirus, which has caused us significantly greater problems with its death rate of around 1% compared to SARS, MERS and Ebola, whose death rates were 10%, 35%, and about 50%.When the virus arrived in Europe, my concern over the speed of its spread has, unfortunately, came to fruition. The virus’ “spread rate” seemed to be underestimated initially. Its rapid spread made the novel coronavirus significantly more dangerous than its “death rate” did. Initial estimates of the R0 coefficient were around 2.2, but in my own calculations the behavior of the virus in Europe was more consistent with the values within the range of 2.5-4.0, if not more . This meEpidemiologists would be very happy if they could answer positively and say that this was the end of a major public health emergency. However, many things related to this pandemic are considerably more complex than typical public communication related to most other issues. Therefore, the conclusion that follows from the reduced estimates of the “death rate” is still not all that simple.Unlike other diseases that health care systems regularly face, COVID-19 also has a “fourth dimension” − time. It uses this additional dimension to cause problems that we are simply not used to. In medicine, doctors see too many cases of a certain illness at the same time when, eg, the trauma clinic needs to deal with injured people from a large train or bus crash and they do not have sufficient capacity to help everyone. Another example is wartime surgery, where several military surgeons would need to deal with the sudden emergence of a large number of wounded soldiers following an unforeseen battlefield tragedy. But beyond those rare examples, having too many patients with the same life-threatening condition at the same time is not something that medical professionals often need to worry about.So, let’s suppose for a moment that this relatively small “death rate” of somewhere between 0.5% and 1% for most western populations is really the only danger associated with it. Then, the new coronavirus could be compared to a monster slowly approaching us from afar. We can see increasingly clearly that the monster is physically small, it reaches only up to our waist. So, we begin to relax. We assume that we should be able to knock something that small to the floor and master it. But, we are only looking at it from the front as it approaches. We cannot check what it has behind its back. There, in a dimension we cannot see, this short monster is hiding three metal bars. When the monster finally stands right before us, if we let him out of our sight for one moment, he will be able to hit us over the head with one of these metal bars at an unbelievable speed.The first problem that the new coronavirus causes us from that fourth dimension, beyond the death rate itself, is its rapid spread. If we allow it to spread freely among the population, it will infect hundreds of thousands from just one infected person in only a matter of a month or two. Even with a small “death rate”, it will soon lead to thousands of severely ill patients who would require intensive care. All those who do not receive care would then die of suffocation. They would die alone in hospitals because their families would not be allowed to the infected wards. The burial conditions of all the deceased would also be limited and quite different from the usual customs. This is not a fate that anyone would wish on an older member of their family, so it should be avoided.Another big problem is that the new coronavirus has two faces. When it spreads in the community it is relatively harmless, causing mild to moderate symptoms in most people. But, when it enters into a vulnerable population, such as hospital wards, rehabilitation centers, or retirement homes, it spreads at a tremendous rate, because everyone is particularly receptive. The main problem, though, is that the coronavirus “death rate” then increases by at least ten or twenty times. Among such subgroups, it can kill up to every fifth or tenth infected person, depending on how old and sick they already are. In many European Union countries, a considerable proportion of the total number of deaths was caused by severe outbreaks occurring in retirement homes.The third metal bar this little monster has in its arsenal is the indirect effect of the virus on the health system, which causes mortality from all other diseases to increase. Specifically, if the virus was simply allowed to spread freely, hospitals would temporarily be crowded with infected patients, doctors, nurses, as well as people who come for check-ups or visits. Many health care professionals would end up either on sick leave due to COVID-19 or in self-isolation so as not to spread the infection to patients in serious conditions. Many patients would then be moved out of hospitals for home care. A disruption of the health system would cause those with other health conditions to die more frequently.These are the three big problems that no one has a clear answer to yet. This is also why more or less everyone has resorted to a lockdown. The virus is still among us and we have seen at what speed it will continue to spread if we allow it to do so. The first lockdown allowed time to plan the support for the economy, too. However, a second lockdown would really hit the economy hard and frustrate tourism and many other businesses globally.First, not all uninfected people are in equal need of protection. The most important group of uninfected people are immunocompromised people − hospital patients in transplant wards, patients with chronic lung or kidney disease, diabetes or cardiovascular disease, especially those with high blood pressure, patients with malignant tumors receiving radiation or chemotherapy, as well as anyone over seventy years of age .They should be particularly protected from infection if they already have a chronic underlying illness and if they live together in large numbers in retirement homes. These are uninfected persons who should really avoid contact with infected persons. In this next phase of the fight against COVID-19, the successes of individual countries will be measured first and foremost by how well they have managed to protect their hospitals and retirement homes.Then, most of the ambiguities after the lockdown were related to whether or not people could leave their homes, sing on windows and balconies, whether they should wear masks, gloves, and how to dispose of shoes; and whether or not we should disinfect packaging from grocery stores.We are being confronted with a virus that has shown that it spreads rapidly and very successfully among humans, and it was not yet clear how. Such viruses are usually transmitted by droplets of exhaled air, but also by fingers after someone who is infected touches their eyes or their mouth and nose. We can expect the presence of the virus in tears, mucus from the nose, and in saliva. Another person may inhale it, but also touch the location or object that an infected person has previously touched.What does this mean for the issue of leaving homes? Theoretically, it is possible to breathe in the air where someone has previously coughed or spoken loudly. Also, it is possible to touch the handrail where someone infected had touched it before. The same is true for door handles. The risk of being infected in this way is, of course, very low, but the transmission of the virus in such a way is not entirely impossible.Many people need to move and exercise to maintain good health. For this reason, it’s difficult to make a strict recommendation that would apply in all situations and for everyone. For older people, it is certainly better to stay indoors, while for younger people, it is probably better to accept a low risk, go out, and maintain health.There were a lot of ambiguities surrounding the issue of face masks. There are several sub-questions that should be distinguished. First, do masks primarily serve to protect us or others? If they serve to protect ourselves, then they need to be special, more expensive masks. But in that case, everyone should wear them. As it is difficult for each country to plan for the procurement of special protective masks for all of its citizens, especially since they also have a shelf life, personal protection masks from infection are procured and kept for health care professionals. They will certainly be exposed to infected people. Such protective masks should also be distributed to those who are particularly at risk because of their age or their state of health.For everyone else, if they were just walking down the street, protecting themselves in such situations is not as important as the above examples from an epidemiological point of view. It is much more important, however, that someone who is infected but has no symptoms does not go on to infect others. Since we cannot know who is infected until they present with symptoms, it is reasonable for everyone to cover up their mouth and nose in some way so as not to inadvertently spread the infection to others.So, whatever can be done to make it more difficult for the virus to jump from one person to another, should be done. The reason why in many countries there is no strict recommendation on wearing masks is that medical recommendations need to be made on the basis of solid scientific evidence. However, in the case of mask effectiveness, it’s difficult to obtain a sufficient type of evidence when the required outcome of the study should be whether or not there is more or less contamination. When it comes to such research, it would be difficult to grant ethics approval to conduct it.Therefore, what we know about the effectiveness of masks is based on studies that were not optimally designed, which is why it is difficult to get a firm recommendation from any official body. Epidemiologists believe that masks will help to lower the spread of the infection and that people should cover their nose and mouth so as not to accidentally infect others, especially if they are indoors. They can also use a scarf, a handkerchief, a surgical mask, or anything that would help towards this aim. Common sense suggests that any disruption of the viral spread will help combat this pandemic, even where we do not have the solid scientific evidence we would like in order to make for such a recommendation.Similar to the question of singing on balconies or going out for a walk, the risk of getting infected through touching packages in supermarkets is probably very small, but until it is better explored, it cannot be completely ruled out. However, those who become infected in this way are likely to have a significantly lower initial entry dose of the virus than via inhaled air. Therefore, the course of the disease may be milder, although science has yet to confirm that hypothesis. But it would be no surprise to epidemiologists if this was proven, although it should always be reiterated that surprises are always possible with new viruses.A great deal of scientific research on COVID-19 is currently being conducted in a way that would be quite unacceptable to rigorous science under usual circumstances. All work seems to be done at speed, using very small samples that are often not sufficiently representative for the general population. This highlights only some of the imperfections of COVID-19-related research. Many details that must normally be carefully considered in study design are being neglected in the interest of speed. This led to a parallel epidemic of superficial research, seeking to answer the open questions as soon as possible. Unfortunately, a quick-but-wrong answer can do more harm than the one that is obtained more slowly, but which ends up being correct. But decision-making needs are time-sensitive, which should also be appreciated. This is why decisions in this crisis would often be made using suboptimal information.An additional issue is that just about every piece of published research received immediate and massive media attention globally. This drove researchers to publish so-called “pre-prints”. Those are scientific papers that anyone could write and publish on a platform for pre-publications, without them being subjected to a serious scientific and professional scrutiny through peer-review. Scientists are trained to understand whether those pre-prints are serious research or have major shortcomings. However, journalists and the general public will have a much harder time assessing that. Therefore, we entered a cycle of daily media reports on various “scientific discoveries” which either proved false or unfounded in about a week or two. It’s a shame that so much time and media space was devoted to unfounded reports and results. It was one of the basic features of the “infodemia” that has now taken hold.One research question worth exploring is whether the virus can return and infect again those who have already had COVID-19 and were negative on their coronavirus tests . This isFurthermore, it is becoming less likely that the virus will disappear with the arrival of warmer weather. Recent data from West Africa and many other very hot and humid places show that it is spreading rapidly and successfully .The antiviral drug lopinavir, which works by inhibiting proteases, and together with ritonavir, which is effective against the HIV virus that causes AIDS, has not shown efficacy against COVID-19 .Comparison of the data from China, Italy, Spain, and the US have shown that the new coronavirus has not mutated in terms of a higher “rate of death” or a higher “rate of spread”. Its genome seems to be considerably more stable than that of the flu virus .In addition, there are very early first indications that science has yet to confirm through a proper study design that blood plasma transfusions from those who have recovered from COVID-19, through early-response circulating antibodies, may give a bit of hope to severely ill coronavirus patients. However, the samples which were studied were so small that this line of research needs further work .The most promising story from March and April was the initial efficacy of the antiviral drug Remdesivir. This drug is quite elegant in its approach to prevent RNA viruses from replicating. It is an adenosine analogue and is inserted into the strands of the viral RNA molecule, causing the premature termination of protein synthesis. It was supposed to be a cure for Ebola, but it did not show the desired efficacy against that disease .In the first-ever study among severe COVID-19 patients, which was not designed as a properly controlled trial, it showed possible efficacy in about two-thirds of severe coronavirus patients. The study reported that the death rate of those on respirators decreased from about 50% to 15% . BecauseThe reasons are quite complex and I explained them in great detail in two separate articles ,35. TherAlso, the reasons why Italy and other European countries were late with resorting to lockdowns are also complex. They had to do with interactions and communication between politicians, epidemiologists, and the representatives of the private sector. In eastern Europe, it is possible that there was less consideration of “saving the economy”, and more of “protecting the people” during critical decision-making processes that were happening under pressure and great uncertainty described earlier .However, the most important individual factor that determined the epidemiological situation in western and eastern Europe during the first wave of the pandemic was the pattern of population mobility. Western European countries that had lots of air travel with China and also heavy traffic in all forms between themselves in February and early March had a lot of infected cases imported. At this time of the year, countries of eastern Europe had considerably less traffic through their borders. Wherever there was more international traffic, there was more virus imported, and vice versa. Then, the key factor of the eventual success was the response. If the “first line of response” worked well through February and early March and then the lockdown was introduced timely, the results in containing the epidemic were excellent . If “tesAt this point in time, we can only discuss the epidemiological aspects of this approach. The medium- and long-term consequences on the Swedish society will require time to be properly assessed. To understand the epidemiological context, when a situation arises in Sweden where the involvement of experts is required, politics does not interfere in principle. Thus, the Prime Minister left the problem of the COVID-19 pandemic to the state epidemiologist from the National Institute of Public Health, who started planning for achieving “collective immunity though infection” .To many epidemiologists in other countries, this sounded unusual. In principle, “herd immunity” can be achieved by gradual infection. But it is used in public health practice primarily as a principle that prevents mass population infection by vaccination. If everyone needs to be infected to reach that threshold, then “herd immunity” is simply a consequence of mass infection, as if the health care system did not even exist, leading to an unpredictable number of victims .In addition, the proportion of the population that needs to be infected to achieve “herd immunity” depends on the R0 parameter of the new coronavirus, which was not known with sufficient certainty at the time. When R0 is about 2–3, then it is enough to infect about 60% of people. But if R0 is about 5–6, and it could be, then up to 80% or more of people. Therefore, planning for “herd immunity” without a more clearly defined R0 value was actually infecting the population rather blindly − the target proportion was unknown, and so was the number of potential victims.According to the World Values Survey, Swedes show a unique combination of trust in public institutions and extreme individualism . This isIn other EU countries, most cases of the virus spread indoors and within families. Sweden had a big advantage there. Furthermore, Sweden is also known for its immigration programs for highly educated staff from all over the world, in order to balance its labor market. As a result, as many as a quarter of Sweden’s population are relatively young immigrants, most often living in large cities . They beAt the same time, the “death rate” among all infected (IFR) was uncertain. For the new virus, no-one knew what the denominator for calculating the IFR rate really was, because tests to determine the antibody in the blood were not yet available. Events in Italy at the time suggested that the IFR might be as high as 2%, 3%, or even higher. That is why thinking about “herd immunity” without greater certainty in the parameters of R0 and IFR was quite a gamble. An increasing number of scientists and doctors began to protest and put pressure on the Swedish government. As many as 2000 eventually signed a petition . The Prist of April population was banned from visiting retirement homes, after it became clear that the virus had already penetrated half of those homes in Stockholm [As of the 29th of March, the Swedish government has banned public gatherings of more than 50 people. Clear recommendations have also been introduced for people over the age of 70 not to leave their homes if they can avoid it. All who can are invited to work from home, avoiding all trips that are not necessary, and tend to be outside the house only when they are not crowded. Sanctions were indicated for non-compliance with these measures ,41. As otockholm ,41. TherAs a result of this controversy in the media, many citizens − especially the elderly − withdrew to their homes and further strengthened the quarantine nature of the “Swedish model”. It should be understood that, after all these events, nothing so different is happening in Sweden from other countries, so we should expect similar outcomes. However, the media of many countries, as well as individuals on social networks, continued to write about the “Swedish model” myth for various reasons and motives. Some saw a good alternative story in this − “alone against all”, or “no social distancing measures are needed”. Others had simply felt anti-lockdown for various reasons, so they promoted the myth of “no measures in Sweden” to undermine the work by epidemiologists in their own countries. But this is just another in an endless series of insufficiently accurate information that this crisis abounds in. Fortunately, reasonable solutions eventually prevailed everywhere, even in Sweden itself.First, health promotion activities aimed to facilitate broader adoption of ‘’gap maintenance”, ie, keeping a safe distance from each other. Also, people will need to consider covering their noses and mouths, washing hands, wearing gloves, and acting with caution and responsibility. This alone will significantly reduce the viral spread.Then, testing, tracing, and isolating capacity should be enhanced in each country so that they could follow the good examples from South Korea, Taiwan, Japan, and Singapore, who rely mainly on the strength of their first line of defense. They all work hard to constantly “cut paths” for the virus in its spread. Technological solutions are likely to be developed to quickly identify and isolate infected contacts.If the virus turned out to be considerably more dangerous than we thought, or if it spread much faster, then we would need further approaches to ensure population safety. If we ever become confronted with a virus that kills many more among those infected, innovative defenses could then even consider “dividing” the population into several separate subgroups to “dilute” the people who are available to the virus. This would turn any nation that chooses this approach into a so-called “metapopulation”. Subgroups would be able to leave homes and work on different days.This approach is similar to a ship or submarine that is internally divided into bulkheads, so they can protect it from sinking if the hull breaks somewhere. That way, if a considerably more dangerous virus triggered an epidemic within one of these subpopulations, it would not spread to the others. A two-day working week during alternate days for every subpopulation may prevent the virus from spreading day-by-day and growing exponentially. Clearly, this is a measure for the worst-case scenarios and more dangerous viruses. “Metapopulation approach” would still allow nine working days a month, with additional work from home where possible.The combination of all of these measures: (i) the continuous, active detection of infected persons and their separation; (ii) a “safety net” of about 10 000 people for continuous nationwide testing; (iii) splitting the whole of the population into sub-populations, if the virus proves more deadly than we think; (iv) a range of measures to avoid social contacts, such as banning large public gatherings, recommendations on wearing masks and gloves, and restrictions on travel and quarantine for arrivals from abroad; and (v) various innovative technological solutions, such as applications that inform all residents of the status of infection of people they have in their contact list, all of which seem feasible.This would probably protect us enough from the virus and allow the vast majority of people to continue, more or less, with life as much as possible. Then, the hope remains that during the warmer weather the viral spread would slow down at least somewhat. People will need to get out of lockdowns as soon as possible, so these plans for post-lockdown coexistence with the virus need to be made now.Several exit strategies were being considered in most countries during the lockdown. The first one was “complete virus elimination”. This is clearly not eradication, because eradication depends on all countries eliminating the virus. This no longer seems possible until we get a vaccine, but elimination within the country’s borders is a desirable solution if realistic. It requires early quarantine, prolonged high level of discipline of the population, a strong economy that can withstand the quarantine and geographical location that facilitates future surveillance on virus entry and its control using only the “first line of defense”. This kind of approach could lead to ”corona-free zones” all over the world that could exchange people and goods without any concern over the SARS-CoV-2 spreading. Iceland, New Zealand, and Cuba are ideally placed to consider this strategy.The second potential exit strategy which is proactive and maintains an upper hand over the virus is building a strong “first line of defense”. This requires a series of measures that would lead to long-term coexistence with the virus, but prevent its explosive spread to avoid quarantine. It proved to be a highly effective approach in Taiwan and South Korea, which are its global champions.The third possible strategy following the lockdowns is “loosening and tightening / limited lockdowns”. It is a realistic option but it leaves human populations in a subordinate position to the virus. The viral spread will continue to dictate daily lives in all these countries. Still, in the absence of capacity to consider better strategies, this is the only realistic option for most countries globally.Finally, there is an option that may become increasingly attractive to some countries, which could be called the “liberalization of personal risk management”. If the unfortunate situation of the pandemic prolongs and no drugs or vaccines become available anytime soon, some countries may begin to consider granting the right to its citizens to become infected with coronavirus if they so wish. It would mean letting the adult citizens personally assess the acceptable risk for themselves, as well as for all the people they care for, and then adjust their behavior accordingly to that accepted risk.This last option would require a very close and trusting relationship between governments and their citizens in which information on the epidemiological situation would be assessed and clearly communicated to the population on a daily basis. Then, citizens would respond to this information by collectively taking more or less risk. If this was applied properly, it could keep the spread of the virus within acceptable limits, while optimizing people’s movement and work according to the risk that is acceptable to each individual and that would respect vast individual differences in circumstances. This would be a more efficient way of coexisting with the virus than the anti-epidemic measures that would be applied to everyone, regarding of their differences in risk.At the end of the first phase, in which the virus spread initially, and the second phase during which it was slowed down through lockdowns, the novel coronavirus SARS-CoV-2 will likely split the countries into two very broad groups. The first group will comprise countries that prepared very well and reacted early to the epidemic. They focused on managing the epidemic and “crushed the epidemic curve”. This will likely also reduce the impact on their economies. The second group of countries was those that considered alternative options and/or reacted too late, or that simply neglected the problem. Those countries will have high numbers of infected, many deaths, and prolonged lockdown. The impact on their economies is still likely to be substantial. So, the first likely lesson will be that it is better to confront any emerging public health problem, learn about it, and deal with it, rather than neglect it.Second, perhaps this unusual situation will be a historical reminder to both countries and individuals of the importance of self-sustainability and independence from others. Against the trends that globalization brought about in recent decades, this situation led countries to close borders. Then, they suddenly depended entirely on their local production and realized that they had a problem if they had entirely outsourced it to other countries.This situation may also lead many people globally who will be left without work to consider moving back to villages and reverse the trend of urbanization. Now that wireless internet can be accessed everywhere, it almost does not matter where any person on Earth actually lives. But if they have their own garden and well, at least they will not find themselves in an awkward situation that many may find themselves in these days.st century.Perhaps one of the consequences of this crisis will be some new idea of organizing the lives of individuals and countries, based on self-sustainability. This would make them, at least in principle, more robust in the face of a number of possible new challenges of the 21Coronavirus will cause losses for humanity in 2020 on the one hand, but it will reduce losses on the other. For example, it will reduce the number of traffic accidents, the number of victims of violence, and deaths from polluted air. In addition, until recently there were political fights around every percent reduction in fossil fuel use. Now, all of a sudden, this reduction came in an enforced and massive move. In a rather improbable way, this pandemic at least helps combat humanity’s climate change problem.


All three subfamilies  of herpesviruses undergo a maturation phase during replication that initiates in the nucleus of the infected cell with encapsidation of viral DNA to form nucleocapsids. These nucleocapsids are transported across the nuclear membrane into the cytoplasm utilizing a sophisticated nuclear egress complex (NEC). Cytoplasmic phase of virus maturation includes tegumentation and envelopment of nucleocapsids. Herpesvirus tegument proteins play important roles in maintaining the stability of capsids and directing the acquisition of virus envelope. The maturation concludes with the envelopment of nucleocapsids, which occurs at modified host membranes in the cytoplasm and exploits host vesicular trafficking. The entire process of virus maturation is orchestrated by protein-protein interactions and enzymatic activities of virus and host origin.Close et al. focuses on the contribution of endocytic recycling compartment to human cytomegalovirus (HCMV) maturation and egress. They make a strong case that cellular transport systems are engaged by HCMV in a systemic manner for successful maturation and egress. They utilize tools in advanced transcriptomics and proteomics married with computational analysis to come to these conclusions. Earlier studies by the same group as well as other groups have alluded to this engagement process. Close et al. argue that the composition and behavior of endosecretory organelles change during the biogenesis of cytoplasmic virion assembly complex . Infection-associated changes in gene expression suggest shifts in the balance between endocytic and exocytic recycling pathways, leading to the formation of a secretory trap within the cVAC. Also, a shift toward outbound secretory vesicle trafficking indicate a potential role of cVAC in virion egress. The analysis of signaling pathways lead them to model the behavior of endocycling recycling compartment (ERC) during HCMV replication.Herpesvirus maturation remains one of the least studied yet most complicated part of virus life cycle and numerous host and viral factors appear to influence the outcome. The current collection contains three articles contributed by nine authors. These articles have already gathered nearly 5,000 views and continue to gather attention from scientists and non-scientists alike who are willing to delve deep into the mysteries of herpesvirus maturation. The first article by Grosche et al. discusses HSV-1 replication in monocyte-derived dendritic cells (DCs). HSV-1 completes its gene expression profile in immature as well as mature DCs; however, lytic infection only occurs in immature DCs and mature DCs fail to release infectious progeny into the supernatant pointing toward differences in virus maturation and release. This article provides a commentary on viral as well as host factors responsible for these differences.The article by Heilingloh and Krawczyk focuses on the significance of production of non-infectious L-particles during HSV infection and discusses their biological functions. These particles are mostly composed of viral tegument proteins and are devoid of viral DNA and capsids. L-particles seem to undergo similar maturation and egress as the infectious particles and their generation is therefore interesting to investigate in order to understand the process of virus maturation.The article by We believe that maturation of herpesviruses will be an area of continued interest in virology as new virus and host players continue to emerge. The dramatic reorganization of the host endosecretory system leading to the formation of cVAC has mainly been appreciated in HCMV infected cells and deemed as the site of virion assembly. The debate is still on the floor whether this cVAC is a functional component of the virus maturation pathway or is merely an after-effect of virus replication. Although a typical cVAC is not seen during infection with other herpesviruses, a perinuclear site of virus maturation in cytoplasm has been recognized in most. Future studies in this area should focus on the identification of functional interactions among host and viral factors that determine virus maturation as well as structural characterization of the site of virus maturation in cells using advanced techniques in fluorescence and electron microscopy.All authors listed have made a substantial, direct and intellectual contribution to the work, and approved it for publication.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Early maternal separation may have long-lasting physiological effects on different organ systems. Although long-lasting effects of early maternal separation are mostly studied in connection with the development and function of the central nervous system hypothalamic–pituitary–adrenal axis, animal health, behaviour and productivity, there is a lack of information about its impacts on the reproductive system. In the dairy industry, calves are often separated from mothers 1 or 2 days after birth and are not nursed. In the present retrospective study based on data from an artificial insemination (AI) centre, we compared semen parameters and fertility in bulls that were separated from their mothers one day after birth with the semen parameters of bulls that remained with their mothers and were nursed for approximately 2 months. Semen parameters were followed in 3 consecutive years in 52 maternally separated and 22 nursed bulls.Ejaculate volume and total sperm count in ejaculate were significantly higher in nursed bulls in comparison to maternally separated bulls at the age 25–36 and 37–48 months, but interestingly, not at the age 12–24 months, during the first year in the AI centre. Non-return rates did not differ between separated and nursed bulls.The results suggest that early maternal separation causes long-lasting effects on the functioning of the male reproductive system, evident by reduced production of semen in adult bulls. The data suggest that with a standard of 20 million sperms per straw of frozen semen, 27–78 fewer straws can be obtained from one ejaculate of maternally separated bulls in comparison to the nursed bulls. At many dairy farms, separation of calves from cows immediately after birth is a common practice. Instead of suckling with their mothers, calves are fed with milk or milk substitute by milk feeder until they begin to consume hay or silage.Many studies in rats and mice have shown that early neonatal maternal separation is associated with altered behaviour and neuroendocrine responses in adulthood. Early maternal separation causes postnatal stress and permanently alters the hypothalamic–pituitary–adrenal (HPA) axis, resulting in higher basal plasma ACTH levels and a blunted response to stress in the adult animal . It alsoStudies addressing the impact of maternal separation on adult cattle have mainly focused on health, welfare, behaviour, and productivity , 13. A sIn the present study, we compared semen quality parameters of bulls that were nursed by their mothers as calves or were maternally separated a few days after birth. We hypothesized that if early postnatal stress caused by maternal separation permanently or transiently affects the HPG axis, this will be reflected in the bulls’ semen quality.Data on semen quality were collected at the artificial insemination (AI) centre in Preska, Slovenia. The owner of the bulls (AI Centre Preska) provided the data and gave us consent to use the data freely for research purposes.Since this was a retrospective study using data obtained during regular procedures with bulls in the AI centre, no animal experiments were performed for the purpose of this study and therefore, no ethical approval was needed.In total, 74 Brown Swiss bulls were included in this study, of which 52 bulls were separated from their mothers one day after birth and fed with milk or milk substitute using milk feeders. Twenty-two bulls remained with their mothers and were nursed for two months. All bulls were relocated from the home farm to the rearing facility for young bulls. The age of bulls at the relocation was 84–153 days.At the age of one year (± 10 days), the scrotal circumference was measured by measuring tape at the scrotum’s widest point.At the age of 12—14 months, bulls were relocated to the AI centre. During their stay they were tethered in individual boxes. They were fed 9–10 kg of hay and 1.5 kg of complementary feed twice per day and had drinking water ad libitum. Bulls were provided with all the necessary veterinary care. All bulls were subjected to the same standard mounting procedure with the same intervals (3–4 days) between two semen collections. In some rare cases, the interval between two ejaculations in some bulls was longer because of health issues. During semen collection, bulls were mounting a teaser animal. One or two ejaculates on a single day were collected using an artificial vagina. In this study, data of semen parameters during the first and second ejaculations were analysed. In total, data from 4085 ejaculates from the 52 maternally separated bulls and 1210 ejaculates from the 22 nursed bulls were included. The semen parameters were further divided by bulls’ age into three groups: 12–24, 25–36, and 37–48 months of age.Ejaculate volume was determined directly from the graded collection tubes. Sperm concentration in mL of semen was evaluated by a photometer . Total sperm output was calculated by multiplying ejaculate volume and sperm concentration.Further, the fertility of both groups of bulls was estimated by a statistical comparison of the non-return rate (NR (%)) for a period of 90 days.post-hoc Tukey–Kramer test. Data for the scrotal circumference and NR were analysed by one-way ANOVA, followed by post-hoc Tukey–Kramer test. Results are shown as mean ± SE. Pearson correlation coefficient was calculated to determine the correlation between scrotal circumference at 12 months of age and average semen volume, sperm count, and sperm concentration during the age of 12 to 24 months. Differences were considered statistically significant with P < 0.05.All data for semen characteristics were analysed using repeated measures ANOVA with the age and management conditions  conditions as independent variables, an individual bull as a subject variable, and consecutive semen collection (the first or second ejaculation) as within factor. ANOVA was followed by a R2 0.05, 0.137, and 0.008, respectively.Scrotal circumference at 12 months of age was 35.5 ± 0.3 cm in maternally separated bulls and 36.5 ± 0.4 cm in nursed bulls. The values did not differ significantly. There was no correlation between scrotal circumference and average ejaculate volume, sperm count, and sperm concentration with post-hoc test revealed no difference in semen volume in 12–24 months old bulls, but there was a significant difference between nursed and maternally separated bulls at 25–36 and 37–48 months of age.Repeated measures ANOVA analyses of semen parameters revealed that nursed bulls had a significantly higher total volume of collected semen in comparison to maternally separated bulls Fig.  with a spost-hoc test revealed a significant difference between nursed and maternally separated bulls in total sperm count in 25–36 and 37–48 months old bulls, but not at 12–24 months of age.Similarly, total sperm count in ejaculate was different between groups with a significant effect of management conditions (P < 0.05), age (P < 0.05), and interaction between management conditions and age (P < 0.05). The post-hoc test revealed that concentration was significantly different in each age group regardless of management conditions.The concentration of sperms did not differ between nursed and maternally separated bulls Fig. . HoweverThe mean NRs (%) for maternally separated and nursed bulls were 71.6 ± 1.47 and 72.6 ± 2.04%, respectively. The values did not differ significantly.We evaluated whether management conditions affected ejaculate volume, sperm concentration, total sperm output, and motility and fertility expressed as NR in Brown Swiss bulls. All bulls were from an AI centre and were as calves separated from mothers on the first day after birth or were nursed for 2 months.Many studies have shown that neonatal stress has long-lasting consequences for the development of the brain and neuroendocrine system. Although the vast majority of these studies were performed in laboratory rodents, some studies also showed the effects of maternal separation in other animals such as pigs , 18 and We observed highly significant differences between nursed and maternally separated bulls in the ejaculate volume and in the total sperm count in the ejaculate, but not in the concentration of sperms. Interestingly, these differences were observed only in 25–36 and 37–48 months old bulls, but not in 12–24 months old nursed and maternally separated bulls. These results suggest that maternal separation influences gonadal development and sperm production, although, at present, it is not known how and through which mechanisms. As this was a retrospective study, we could not obtain blood samples to determine the levels of sex hormones. Therefore, further studies will be needed to examine whether neonatal stress perhaps permanently alters levels of hormones such as testosterone and follicle stimulating hormone (FSH), which are known to regulate spermatogenesis.Wagner et al.  reportedScrotal circumference is usually linked to sperm production capacity. Several studies reported a significant correlation between scrotal circumference and semen parameters with ejaculate volume and total sperm output closely related to the testes size , 23. In Intriguing is the observation that differences in semen parameters were significant in bulls from 25–48 months of age, but not in 12–24 months old bulls. Bulls normally enter puberty around 9–10 months of age when they can produce their first ejaculates, but their reproductive tract continues to develop, and the capacity for sperm production increase for an extended period after the beginning of puberty. Scrotal circumference increases at least until 30 months of age, while sperm production  increases up to 5 years of age , 20. A rNR rate shows the percent of successful first inseminations with the semen of a particular bull. Although NR is influenced by several factors such as AI service, heat detection, and cows’ health, it is an important parameter for evaluating bulls’ fertility. Statistical analysis showed no significant differences in NRs between maternally separated and nursed bulls. Therefore, these results suggest that rearing conditions did not affect the fertilizing ability of sperms, yet it reduced the production of sperms.Although the bulls’ fertility as judged from the NR rate was not affected by neonatal rearing conditions, the results have important implications for the bovine AI industry. Reduced sperm count in maternally separated bulls does not affect their fertility in natural service. However, a significant difference in total sperm count per ejaculate does reduce the total number of insemination doses obtained from one ejaculate. Our results suggest that with a standard of 20 million sperms per straw of frozen semen, 27–78 fewer straws can be obtained from one ejaculate of maternally separated bulls in comparison to the nursed bulls. Besides the economic impact for semen collection organizations, this also means that maternally separated bulls will produce a lower number of calves what is important for cattle farming if such bulls have otherwise excellent progeny. Therefore, the AI organizations should pay attention to bulls’ neonatal rearing conditions, as neonatal stress could likely result in large and significant differences in total sperm output. We suggest that newborn calves, which will be included in the semen production, should not be separated from their mothers immediately after birth.Further studies will be needed to establish how these effects of early life stress influence the development of the male reproductive tract, but the results clearly show the importance of the neonatal environment for the functioning of male reproductive organs.Early separation of male calves from their mothers influences sperm output in adulthood. Ejaculate volume and total sperm count in ejaculates of nursed bulls were higher in comparison to maternally separated bulls at 25–36 and 37–48 months of age, but not 12–24 months old bulls. Results suggest that early maternal separation causes long-lasting effects on the HPG axis, evidenced by reduced production of the semen in adult bulls. However, further prospective studies will be needed to confirm these results and explore the mechanisms leading to the reduced sperm counts in maternally separated bulls. Besides stress, other factors such as the difference in the nutrients in milk and milk substitute could potentially cause such differences. Nevertheless, the results of this study are important for the insemination industry since 27–78 fewer produced straws can be expected per ejaculate of maternally separated bulls in comparison to nursed ones.


Diameter , sphericity , and rupture strength  were selected as the dependent variables. A decrease in gelation temperature increased the diameter, sphericity and rupture strength of the CAG beads. Additionally, the CAG beads prepared at 5 °C exhibited the highest rupture strength (3976 kPa), lowest calcium content (1.670 mg/g wet), and a regular internal structure. These results indicate that decreasing the gelation temperature slows the calcium diffusion rate in CAG beads, yielding a more regular internal structure and increasing the rupture strength of the beads.Until now, most studies using calcium alginate gel (CAG) have been conducted primarily at room temperature (20 °C) without considering gelation temperature. Moreover, the effects of gelation temperature on the physical properties of CAG beads have not been studied in detail. We aimed to study the effect of gelation temperature on the physical properties  of CAG beads. Response surface methodology was used in this study. The independent variables were sodium alginate concentration (X Calcium alginate gels (CAGs) have been used widely in various fields of biotechnology, including the food, medicine, and pharmaceutical industries, due to their biocompatibility, low toxicity, easy gel formation, and low price ,2. CAG fGenerally, CAGs are prepared as a variety of beads or capsules ,6; howevTo date, in most previous studies, CAGs have been prepared at room temperature (approximately 20 °C) ,11,12,131, 1.2−3.6%, w/v), calcium lactate concentration , gelation temperature , and gelation time , while diameter , sphericity , and rupture strength  were selected as the dependent variables. In addition, to better understand the relationship between rupture strength of the CAG bead and gelation temperature, calcium and sodium ion contents and microstructures of CAG beads were investigated.Response surface methodology (RSM) is an effective mathematical and statistical method to monitor or optimize processes when several factors and interactions influence the process response . Thus, R3; Quality Control Standard-21 Elements, MA, USA), respectively. All other chemicals and reagents used were of analytical grade.Sodium alginate  and calcium lactate were purchased from Junsei Chemical Co., Ltd.  and Daejung Chemicals and Metals Co., Ltd. , respectively. Standard solutions for measuring sodium and calcium ion content were obtained from AccuStandard  and PerkinElmer  coupled to a stereoscopic microscope . The diameter (mm) of the CAG beads was calculated by averaging the shortest and longest diameters, while the sphericity (%) of the CAG beads was calculated as the percentage ratio of the shortest and longest diameters.To determine the diameter and sphericity of the CAG beads, we measured the shortest and longest diameter of ten randomly selected CAG beads with an image analyzer (i-Solutionn = 10) was measured using a rheometer  under the following conditions: MODE 4; adapter type, cylindrical plunger (diameter: 25 mm); compression speed, 60 mm/min; correction, 0.2 N; and load-cell, 0.1 kN.Rupture strength (kPa) is the maximum load applied to the sample area by a plunger when the sample is ruptured and permanently deformed. The rupture strength of the CAG beads , and three replicates of the center point. The independent variables were sodium alginate concentration , calcium lactate concentration , gelation temperature , and gelation time . The ranges of the independent variables and their levels are presented in 1, mm), sphericity , and rupture strength  were chosen as the dependent variables and the run order of the experiment was randomized to minimize the effect of unexpected variables. The experimental data were analyzed using the response surface regression procedure in Minitab statistical software  to fit the following generalized quadratic polynomial model Equation (1):0 is a constant, and βi, βii, and βij are linear, quadratic, and interaction regression coefficients, respectively. Xi and Xj are coded values of the independent variables. Three-dimensional response surface plots were produced from the fitted response surface model equations using Maple software .CCD was used to monitor the effects of different preparation conditions on the physical properties of CAG beads. The CCD matrix was composed to 2The moisture content of CAG beads was determined using a digital moisture analyzer . The temperature of the infrared drying chamber of the machine was set at 100 °C. Measurements were repeated 10 times and 50 CAG beads were used at a time. Fifty CAG beads were dried until there was no weight change of 0.1% in 1 min (based on wet weight). The moisture content was the percentage difference between the wet and dry weight divided by the wet weight.n = 3). The dried CAG beads obtained after measuring the moisture content were collected and used as a dry sample for ICP-OES. The CAG bead preparation and drying process was repeated to collect approximately 0.3 g of dry sample for ICP-OES. Dry samples were completely dissolved in 2 mL ultrapure water, 4 mL nitric acid, and 0.5 mL hydrochloric acid using a microwave reaction system  and then ultrapure water was added to make 100 mL. The sodium ion content of the sample solution was measured at 589.592 nm by ICP-OES, while the calcium ion content was measured at 317.933 nm after the sample solution had been diluted 10-fold. Calibration curves were produced from 0 to 25 mg/L of calcium ions and 0 to 200 mg/L of sodium ions using standard solutions and were used to determine the calcium and sodium ion content. The ion and moisture contents of the dried CAG beads were used to calculate the ion content of the wet CAG beads.Inductively coupled plasma optical emission spectroscopy  was used to measure calcium and sodium ion content  to confirm whether the remaining sodium ions in the beads had diffused out. The CAG beads were then immediately frozen in liquid nitrogen, cut in half, and lyophilized. An energy-dispersive X-ray spectrometer  equipped with a field-emission scanning electron microscope  was used to analyze the sodium ion content of the dried CAG beads at an accelerating voltage of 15 kV.A low-vacuum scanning electron microscope  was used to investigate the effect of gelation temperature on the microstructure of CAG beads. CAG beads prepared at each gelation temperature were frozen and dried using the method described in n = 10) were analyzed. Weights were determined using a digital balance , using Equation (2) as follows:To determine the density, the weight and diameter of CAG beads (1 (diameter) and Y3 (rupture strength) were significant (p < 0.05), whereas the quadratic and interaction terms were not. The constant, X1, X3, X1X1, and X3X3 term coefficients for Y2 (sphericity) were significant (p < 0.05), thus implying a curvilinear effect of X1 and X3 on the sphericity of CAG beads, while all interaction terms for Y2 were not significant. The insignificant interaction terms for Y1, Y2, and Y3 mean that the effects of gelation temperature on the physical properties of CAG beads were not significantly related to the other factors—sodium alginate and calcium lactate concentration and gelation time. The determination coefficient (R2) of the fitted quadratic polynomial model equations for Y1, Y2, and Y3 were 0.913, 0.912, and 0.935, respectively, and the R2 values for all response surface models were highly significant (p < 0.01)  on the physical properties of the CAG beads.We used a three-dimensional response surface plot to visually display the effects of gelation temperature (X1) of the CAG beads increased with increasing sodium alginate concentration (X1) and decreased with increasing gelation temperature (X3). The effect of sodium alginate concentration and gelation temperature on the diameter of CAG beads might be explained by the viscosity of sodium alginate, which increased with increasing concentration or decreasing gelation temperature. As viscosity increased, the size of the sodium alginate droplets on the nozzle tip also increased, thereby increasing the diameter of the CAG beads [1) of the CAG beads decreased when the calcium lactate concentration (X2) or gelation time (X4) increased. These results can be explained by the study of Klokk et al. [AG beads ,26. More2) of the CAG beads increased as gelation temperature (X3) was slightly increased, and then decreased gradually. This is in contrast to the effect of sodium alginate concentration on the sphericity of CAG beads. CAG bead sphericity is closely related to sodium alginate viscosity; the shape of sodium alginate droplets is significantly altered when they hit the calcium lactate solution surface under low viscosity conditions, but sphericity is recovered by increasing the surface tension and gelation above a certain viscosity [4) seemed to increase the sphericity of CAG beads slightly; however, the P-value of the X4 term coefficient for sphericity was greater than 0.05 (2). These results indicate that the shape of the falling sodium alginate droplets is an important factor determining the sphericity of CAG beads, and the influence of other factors is not significant after the formation of CAG beads formed through the reaction between alginate and calcium ions. In this study, CAG beads with sphericity greater than 95% were indistinguishable compared to perfect spheres when observed with the naked eye. Thus, preparation conditions must be carefully controlled to produce CAG beads with excellent visual sphericity.iscosity . Consequiscosity . An incrhan 0.05 . These r3) of CAG beads increased proportionally with the sodium alginate concentration (X1), calcium lactate concentration (X2), and gelation time (X4). These results are consistent with previous studies that determined CAG gel strength according to the degree of interaction between calcium ions and α-L-guluronic acid, finding that strength was directly proportional to sodium alginate concentration, calcium concentration, and the duration of the interaction between alginate and calcium [ calcium ,29,30.3) of the CAG beads increased when the gelation temperature (X3) decreased. Some studies have hypothesized that the increase in gel strength with low gelation temperature might be caused by the formation of a more dense internal structure due to a reduced calcium ion diffusion rate [Gelation temperature is an important factor that significantly affects the rupture strength of CAG beads but has not been studied in detail to date. As ion rate ,32,33; hMoreover, the sodium ion content of the CAG beads was highest (0.278 mg/g wet weight) when the gelation temperature was 5 °C. This might cause the CAG beads to swell because of ion-exchange between the residual sodium and calcium ions and can be a problem for their storage stability ,35. We aNext, we investigated the effect of gelation temperature on the internal structure of CAG beads. To prevent excessive shrinkage during lyophilization and ensure easy cutting, the beads were lyophilized after being halved while frozen ,36. The 3). The optimal X1 , X2 , X3 (gelation temperature), and X4 (gelation time) conditions for preparing CAG beads with a maximum rupture strength were 3.6%, 4%, 5 °C, and 30 min, respectively (1 (diameter), Y2 (sphericity), and Y3 (rupture strength) values were 2.85 mm, 94.5%, and 6676 kPa, respectively. We prepared CAG beads under optimal conditions, yielding similar experimental Y1, Y2, and Y3 values of 2.88 ± 0.01 mm, 97.5 ± 0.9%, and 6444 ± 692 kPa, respectively. Consequently, the percentage error values  among the experimental and predicted values of Y1, Y2, and Y3 were very small, implying that the developed models were considerably fitted [Lastly, we optimized the conditions to prepare CAG beads with maximum rupture strength (Yectively . Table 8y fitted .Here, we showed that gelation temperature is an important factor affecting the physical properties of CAG beads. Moreover, our study demonstrated that low gelation temperatures lowered the calcium ion diffusion rate, yielding a more regular microstructure to CAG beads. For this reason, the rupture strength of CAG beads increased as gelation temperature decreased. Furthermore, the CAG beads produced at a low gelation temperature might contain sodium ions; therefore, appropriate immersion is necessary to release these ions and improve the storage stability of CAG beads. Thus, we suggest that gelation temperature should be considered carefully in future research and development using CAGs.


This cross-sectional study assesses drug coverage, formulary restrictions, median retail prices, and annual out-of-pocket costs associated with commonly used insulin products across Medicare Part D plans. These classes are increasingly used as second-line agents for patients with type 2 diabetes despite only a modest effect on glycemic control (approximately 0.8% to 1%) because of mounting evidence of cardiovascular benefits. We sought to examine contemporary coverage and out-of-pocket costs for beneficiaries filling either an SGLT2 inhibitor or GLP-1 receptor agonist prescription in Medicare Part D.The Centers for Medicare & Medicaid Services recently announced a voluntary plan to cap out-of-pocket costs associated with insulin products in participating enhanced Part D plans.5 to assess drug coverage, formulary restrictions, median retail prices, and annual out-of-pocket costs associated with commonly used SGLT2 inhibitors and GLP-1 receptor agonists  reporting guideline for cross-sectional studies and was determined to be exempt by the University of Pittsburgh institutional review board.We estimated the median annual out-of-pocket costs for Part D beneficiaries not eligible for low-income subsidies for each drug by using 2 approaches: using the 2019 standard Part D benefit design , and using plan-specific benefit information from the formulary files to calculate plan estimated out-of-pocket costs . All analyses were performed with SAS version 9.4 and R version 3.6.1. This study follows the Strengthening the Reporting of Observational Studies in Epidemiology  for ertugliflozin to $2447  for liraglutide with the standard Part D benefit design. In comparison, median out-of-pocket costs with an algorithm based on plan-specific benefits data were lower, ranging from $1097  for empagliflozin to $2080  for exenatide .6 and may be unaffordable for the hundreds of thousands of older adults with diabetes and elevated cardiovascular risk who may receive clinical benefit from one of these newer agents.Coverage for SGLT2 inhibitors and GLP-1 receptor agonists was generally high in 2019 Part D plans, although variable across specific drugs. However, Medicare beneficiaries not eligible for low-income subsidies or Medicaid potentially face very high out-of-pocket costs for SGLT2 inhibitors and GLP-1 receptor agonists. With the exception of less commonly prescribed drugs such as lixisenatide and ertugliflozin, the average beneficiary covered by a Part D plan could spend at least $1000 annually for 1 SGLT2 inhibitor and greater than $1500 for 1 GLP-1 receptor agonist. Although these products are used less frequently than insulin, these annual out-of-pocket costs are on par with—and in some cases exceed—those associated with insulin,Our analysis has 2 main limitations. First, although we weighted our analyses by plan enrollment, we could not account for diabetes-specific enrollment. Second, out-of-pocket cost calculations assumed that beneficiaries only use 1 drug at a time, when in fact older adults using SGLT2 inhibitors and GLP-1 receptor agonists commonly fill other prescriptions, including metformin and insulin. Therefore, our results may overestimate out-of-pocket costs for these drugs among patients who would have reached catastrophic coverage because of simultaneous use of multiple higher-cost drugs. Some beneficiaries may also be insulated from high out-of-pocket costs through patient assistance programs. Although median retail prices do not include proprietary rebates, they do influence the amounts patients pay as coinsurance.


Homo sapiens. Here, we discuss the inconvenient truth of how humans have become superspreaders of plant viruses on both a local and a global scale.Plant viruses are commonly vectored by flying or crawling animals, such as aphids and beetles, and cause serious losses in major agricultural and horticultural crops. Controlling virus spread is often achieved by minimizing a crop’s exposure to the vector, or by reducing vector numbers with compounds such as insecticides. A major, but less obvious, factor not controlled by these measures is  In the year 2020, the world has seen the fast and perverse spread of SARS-CoV-2, which has led to a shutdown of our societies and the loss of 1.3 million human lives worldwide so far [Plant viruses constitute a major cause of plant diseases with an estimated economic impact of more than USD 30 billion annually ,5 and, sWhile the spread of animal viruses is most often associated with direct contact or proximity to infected individuals, plant viruses are transmitted through wounds on the plant or via a vector, most often insects, fungi and nematodes that feed or infect the plant . AlthougThere are several ways in which humans currently affect the spread of plant viral diseases. For example, the exchange of virus contaminated material between people plays a major role in transferring the virus to uninfected plants, most often as a result of limited knowledge in viral aetiology of symptomatic plants. For instance, the initial course for the spread of both African cassava mosaic virus (ACMV)  and sweeAnother common way in which some viruses spread within crop fields is due to poor agricultural practices, such as the usage of unsterilised tools, not clearing plant debris, and even the continuous use of clothes and shoes that have been in the contaminated field ,32. No-tSome plant diseases rely heavily on insect vectors for the transmission of the virus to a healthy plant. Tomato yellow leaf curl disease is one such case where the disease spreads by the feeding of whitefly vector carrying tomato yellow leaf curl virus (TYLCV) . In this2 concentrations, leading to altered rainfall patterns, recurrent extreme weather events, as well as variations in wind velocity and direction [Nicotiana benthamiana [The successful emergence and spread of plant viruses, and that of their vectors, are also indirectly influenced by the behaviour of mankind. Global climate change linked to human activities has increased global temperature and COirection ,34,35. Sirection . For exathamiana ,38; howethamiana . In addithamiana , shorterthamiana  and incrthamiana . Moreovethamiana .Undoubtedly, lifestyle and reluctance to heed science-based information, at both an individual and societal level, have been major reasons contributing to the current COVID-19 pandemic. Modern people are accustomed to frequent domestic and international travel, large gatherings such as sporting events and concerts, all of which have played a central role in how fast and far the virus has spread. Similarly, the transmission of exotic plant viruses across local and international borders has been aggravated along with increased global trades of food and agriculture products. In addition, food items infected with viruses can easily travel across borders with the world’s population travelling more often and further. Overall, trade-in plants, plant products, and the movement of people are accountable for the 71% of factors known as routes of emerging plant viral diseases, while 16% is due to change in the vector populations . A few eThe COVID-19 pandemic has shown us the importance of containment measures, such as self-isolation and quarantine, in halting the spread of the disease . The samHomo sapiens, the superspreader of plant virus diseases.Ultimately, unless the threat of virus infection of food crops is perceived to be of sufficient impact , changing human behaviour in order to minimise crop losses seems less likely to be achieved than the development of crops with new sources of virus or vector resistance. To finish on an optimistic note: never before has humanity possessed such extensive genomic information and insights about crops, their wild relatives, their pathogens and their pests; nor has it possessed such powerful molecular and genetic technologies for accelerated breeding and synthetic biology. It is probably with this information and these tools that resilient crops can be developed to increase sustainable food supplies to such a level that they offset the damages wrought by