+Summary of impacts for<unk> *(WHO's update, 24 August 2021) Transmissibility Increased transmissibility and secondary attack rate, similar transmissibility between vaccinated and unvaccinated individuals. Virulence Increased risk of hospitalization Reinfection Decreased neutralizing activity Diagnostics No impacts yet reported * Transmissibility UK scientists have said that the<unk>  variant is between 40% and 60% more transmissible than the previously dominant Alpha variant, which was first identified in the UK (as the Kent variant). Given that Alpha is already 150% as transmissible as the original SARS-CoV-2 strain that emerged in late 2019 in Wuhan, and if<unk>  is 150% as transmissible as Alpha, then<unk>  may be 225% as transmissible as the original strain. BBC reported that basic reproduction number, or the expected number of cases directly generated by one case in a population where all individuals are susceptible to infectionfor the first detected SARS-CoV-2 virus is 2.4-2.6, whereas Alpha's reproduction number is 4-5 and<unk> 's is 5–9. These basic reproduction numbers can be compared to MERS (0.29-0.80), seasonal influenza (1.2-1.4), Ebola (1.4-1.8), common cold (2-3), SARS (2–4), smallpox (3.5-6), and chickenpox (10-12). Due to<unk> 's high transmissibility even those that are vaccinated are vulnerable, albeit to a lesser extent. A study published online (not peer-reviewed) by Guangdong Provincial Center for Disease Control and Prevention may partly explain the increased transmissibility: people with infection caused by<unk>  had 1,000 times more copies of the virus in the respiratory tracts than those with infection caused by variants first identified in the beginning of the pandemic; and it took on average 4 days for people infected with<unk>  for the virus to be detectable compared to 6 days with initially identified variants. Surveillance data from the U.S., Germany and the Netherlands indicates the<unk>  variant is growing by about a factor of 4 every two weeks with respect to the Alpha variant. In India, the United Kingdom, Portugal, Russia, Mexico, Australia, Indonesia, South Africa, Germany, Luxembourg, the United States, the Netherlands, Denmark, France and probably many other countries, the<unk>  variant had become the dominant strain by July 2021. Depending on country, there is typically a lag from a few days to several weeks between cases and variant reporting. As of July 20, this variant had spread to 124 countries, and WHO had indicated that it was becoming the dominant strain, if not one already. In the Netherlands, the virus was still able to propagate significantly in the population with over 93.4% of blood donors being tested positive for SARS-CoV-2 antibodies after week 28, 2021. Many people there are not fully vaccinated, so those antibodies would have been developed from exposure to the wild virus or from a vaccine. Similar high seroimmunity levels occur in the United Kingdom in blood donors and general surveillance. A preprint found that the viral load in the first positive test of infections with the variant was on average ∼1000 times higher than with compared infections during 2020. Preliminary data from a study with 100,000 volunteers in the UK from May to July 2021, when<unk>  was spreading rapidly, indicates that vaccinated people who test positive for<unk> ID-19, including asymptomatic cases, have a lower viral load in average. Data from the US, UK, and Singapore indicate that vaccinated people infected by<unk>  may have viral loads as high as unvaccinated infected people, but might remain infectious for a shorter period. Infection age groups Surveillance data from the Indian government's Integrated Disease Surveillance Programme (IDSP) shows that around 32% of patients, both hospitalised and outside hospitals, were aged below 30 in the second wave compared to 31% during the first wave, among people aged 30–40 the infection rate stayed at 21%. Hospitalisation in the 20-39 bracket increased to 25.5% from 23.7% while the 0-19 range increased to 5.8% from 4.2%. The data also showed a higher proportion of asymptomatic patients were admitted during the second wave, with more complaints of breathlessness. Virulence A few early studies suggest the<unk>  variant causes more severe illness than other strains. On 7 June 2021, researchers at the National Centre for Infectious Diseases in Singapore posted a paper suggesting that patients testing positive for<unk>  are more likely to develop pneumonia and/or require oxygen than patients with wild type or Alpha. On June 11, Public Health England released a report finding that there was "significantly increased risk of hospitalization" from<unk>  as compared with Alpha; the risk was approximately twice as high for those infected with the<unk>  variant. On June 14, researchers from Public Health Scotland found that the risk of hospitalization from<unk>  was roughly double that of from Alpha. On July 7, a preprint study from epidemiologists at the University of Toronto found that<unk>  had a 120% greater – or more than twice as large – risk of hospitalization, 287% greater risk of ICU admission and 137% greater risk of death compared to non-variant of concern strains of SARS-COV-2. However, on July 9, Public Health England reported that the<unk>  variant in England had a case fatality rate (CFR) of 0.2%, while the Alpha variant's case fatality rate was 1.9%, although the report warns that "case fatality rates are not comparable across variants as they have peaked at different points in the pandemic, and so vary in background hospital pressure, vaccination availability and rates and case profiles, treatment options, and impact of reporting<unk> y, among other factors." James McCreadie, a spokesperson for Public Health England, clarified "It is too early to assess the case fatality ratio compared to other variants." A Canadian study released on 5 October 2021 revealed that the<unk>  variant caused a 108 percent rise in hospitalization, 235 percent increase in ICU admission, and a 133 percent surge in death compared to other variants. is more serious and resulted in an increased risk of death compared to previous variants, odds that are significantly decreased with immunization.
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