First Ebola Vaccine Likely To Stop The Next Outbreak

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When Ebola struck West Africa a few years ago, the world was defenseless. There was no cure. No vaccine. And the result was catastrophic: More than 11,000 people died. Nearly 30,000 were infected.

Now it looks like such a large outbreak is unlikely to ever happen again. Ever.

The world now has a potent weapon against Ebola: a vaccine that brings outbreaks to a screeching halt, scientists report Thursday in The Lancet.

"We were able to estimate the efficacy of the vaccine as being 100 percent in a trial," says Ira Longini, a biostatistician at the University of Florida, who helped test the vaccine. "It's very unusual to have a vaccine that protects people perfectly."

Now, no vaccine — or drug for that matter — is perfect. The efficacy of the vaccine is clearly high but not "100 percent." That value reflects the fact that they just haven't tested the vaccine on enough people yet. So it is likely to decrease as the vaccine is used over time. In the end, the efficacy is likely to sit somewhere between about 70 percent and 100 percent, Longini says.

By comparison, the flu vaccine last year was about 50 percent effective.

And the Ebola vaccine works lightning fast, within four or five days, he says. So it could even be given after a person is exposed to Ebola but hasn't yet developed the disease.

Longini and his colleagues tested the vaccine on about 4,000 people in Guinea back in 2015, when Ebola was still spreading there. These people were at high risk of getting Ebola because they had had contact with someone who was infected.

When they got the vaccine right away, they were completely protected. No one got sick.

The vaccine — called rVSV-ZEBOV — hasn't been approved yet by either the World Health Organization or the U.S. Food and Drug Administration. That's predicted to happen sometime in 2018.

And there are still a few open questions about the vaccine, says Dr. Anthony Fauci, at the National Institutes of Health.

"For example, we don't know how durable the vaccine is," he says. "If you give health care workers the vaccine, for example, how long would they be protected? That's very important to learn."

What is clear is that the vaccine offers short-term protection during outbreaks. And that's exactly what's needed to stop the virus from spreading and to keep small outbreaks from getting out of control.

For this reason, GAVI — the Global Alliance for Vaccines and Immunization — has already spent $5 million to help finish the development of the vaccine and to stockpile it.

"So we have made 300,000 doses available, as of earlier this year, if there was to be sort of any resurgence or any kind of emergency," says Swati Gupta at Merck, which is manufacturing the shot.

Vaccines typically take years, even a decade to test. But the field trials for this one took less than two years.

"It's been a pretty tremendous experience," Gupta says. "There's been a lot of international partners that have come together in a real unprecedented effort."

The magnitude of the outbreak in West Africa, she says, made companies, governments and academic institutions push aside their own research agendas to come together and finish a vaccine.</s>A Canadian-developed vaccine for the Ebola virus has proven to be extremely effective in a full-scale clinical trial, opening the possibility that future outbreaks of the disease can be successfully contained.

The trial, led by the World Health Organization, was staged in Guinea, a country that was ravaged by the Ebola epidemic that swept across West Africa in 2014-2015.

Reporting Thursday in the medical journal Lancet, the study team found that not a single individual among thousands who received the vaccination as soon as they were identified as being at risk of exposure ended up infected with Ebola. In contrast, a control group that was given the vaccine after a three-week waiting period produced 23 infections.

Study leader Marie-Paule Kieny, the WHO’s assistant director-general for health systems and innovation, said the numbers suggest that the vaccine, called rVSV-ZEBOV, is likely to be more than 80-per-cent effective when deployed across an entire population.

“We may very well have a vaccine that will ensure we can control any outbreak,” Dr. Kieny said in an interview from Geneva.

The vaccine is only expected to be effective against the so-called Zaire strain of the virus that was responsible for more than 11,300 deaths in Western African starting in late 2013 – the worst Ebola outbreak in history. A parallel vaccine is still needed for the Sudan strain, which is more prevalent in Eastern Africa.

The clinical trial, which began in March, 2015, marks the first time any vaccine for Ebola has passed the hurdles required for regulatory approval. Other trials that began around the same time foundered because infection rates in Western Africa were dropping too rapidly by then to provide a statistically significant result.

To overcome the dearth of new cases, the WHO team adopted a “ring vaccination” strategy. The approach was originally devised to help shut down the last remaining clusters of smallpox, leading up to its eradication in 1980. During the WHO trial, only those individuals who were close contacts of a new Ebola case, including family members and neighbours, as well as contacts of those contacts, were vaccinated. Whereas members of a randomly chosen West African cohort might only have a minute chance of contracting Ebola , those in the ring of contacts around a new case would be at much higher risk. This translates into a higher confidence level in results of the trial.

“It was a brilliant study design, given the circumstances,” said Frank Plummer, a professor at the University of Manitoba and former scientific director general of the National Microbiology Laboratory in Winnipeg.

Dr. Plummer was running the federal laboratory when scientists there were developing the rVSV-ZEBOV vaccine, based on work by virologists Heinz Feldmann and Gary Kobinger, among others. The vaccine is an altered form of vesicular stomatitis virus (VSV), which affects animals but not people. Thanks to a genetic modification, it carries a surface protein that is identical to one found on the Ebola virus. The protein serves to prime the body’s immune system so that it recognizes and attacks any real Ebola it encounters.

“It’s like a photocopy of Ebola on the outside but with no Ebola on the inside,” said Dr. Kobinger, now the director of Laval University’s Infectious Disease Research Centre. The vaccine is owned by the Public Health Agency of Canada and was licensed to NewLink Genetics, a small U.S.-based firm, in 2010, at a time when there was little commercial interest in developing an Ebola vaccine. It was in turn licensed to the pharma giant Merck in 2014, which produced the vaccine for the trial. Had the Canadian lab not already been developing the vaccine, it would have taken far longer to get to a successful clinical trial so soon after the outbreak.

“We’d been working on it for almost fifteen years,” Dr. Plummer said. “I think it’s a lesson about the value of investigator-driven research.” He added that the VSV virus may turn out to be similarly useful as a platform for creating vaccines against other deadly infections.

Dr. Kobinger said that there were also lessons to be learned that could help global heath agencies respond faster the next time there is an outbreak for which there is no available prevention. For example, had human-safety tests already been conducted on the vaccine, a clinical trial could have been attempted months sooner, while the outbreak was still growing.

Dr. Kieny noted that there remains more work to do on the vaccine yet, including establishing how long it retains its effectiveness. This will be key for health-care workers in high-risk areas who may come to depend on the vaccine for protection.

But, at the very least, the spectre of another uncontrolled Ebola outbreak is receding. With an unusually expressive remark for a scientific paper, the title of the WHO study includes a nod to researchers’ intense desire to bring a terrifying killer to heel.

“Ebola Ca Suffit!” it reads in French. Ebola, enough already.</s>PARIS: A prototype vaccine for Ebola may be "up to 100 percent effective" in protecting against the deadly virus, the World Health Organization (WHO) said Friday.



If all goes well, the vaccine could become available in 2018 under a fast-track approval process, it said.



In a major clinical trial, nearly 6,000 people in Guinea were given the test vaccine last year, at the tail end of a lethal epidemic of Ebola.



Not one of the 6,000 contracted the disease.



But in a control group of volunteers that did not receive the vaccine, 23 Ebola cases occurred, researchers reported in The Lancet medical journal.



"If we compare zero to 23, this strongly suggests that the vaccine is very effective, that it could be up to 100 percent effective," Marie-Paule Kieny, WHO's assistant director-general and lead author of the study, told AFP.



Her team of three dozen researchers calculated 90-percent likelihood during a full-fledged epidemic that the vaccine, dubbed rVSV-ZEBOV, would work in more than 80 percent of cases.



"After 40 years, we appear to now have an effective vaccine for Ebola virus disease to build upon," Thomas Geisbert, a scientist at Galveston 



National Laboratory in Texas who did not take part in the study, wrote in a commentary, also in The Lancet.



 



First identified in 1976 in what is now the Democratic Republic of Congo, the Ebola virus erupted periodically in outbreaks of up to a couple hundred cases, mainly across west and east Africa.



In early 2014, however, a handful of infections in southern Guinea mushroomed rapidly into an epidemic.

Over the next two years, more than 28,000 people fell ill, mainly in Guinea, Liberia and Sierra Leone. Some 11,300 died.



With a mortality rate above 40 percent, the disease -- one of a category of so-called haemorrhagic fevers -- has an incubation period of up to three weeks. It causes violent and painful symptoms, including vomiting, diarrhoea, organ failure and internal bleeding.



The new vaccine was initially developed in Canada by public health authorities before being taken over by pharmaceutical giant Merck.



It is slated to be submitted by Merck to health authorities in the United States and Europe sometime next year under a fast-track approval process.



"We may have a vaccine which is registered in 2018," Kieny told journalists at a press conference Thursday, noting that the standard approval process for a new drug takes a decade, if not more.



In the meantime, Merck has committed to ensuring that 300,000 doses of the vaccine are available for emergencies under a protocol called "compassionate use".



"They will be able to produce a million in very short period of time," Kieny noted.



 



There are still questions to be resolved concerning the vaccine, including side effects.



Initial tests last year did not include children, while the most recent trials covered those over six years old.



Of the more than 6,000 people injected with the Ebola vaccine only two showed serious adverse effects, the study reported. Both recovered fully.



But it is still unknown if the vaccine is safe for children six and under, pregnant women, or people with the AIDS virus -- all groups that were excluded from the most recent trials.



Another unknown is how long inoculation lasts.



"With the Canadian Merck vaccine, you have a protection very early after vaccination, but we don't know if it will last after six months," Kieny said.



Other Ebola vaccines under development -- some of which have been tested in humans -- could prove more effective over a longer period.



British firm GlaxoSmithKline and Johnson & Johnson, based in the United States, each have experimental products in the pipeline.



China and Russia have also developed vaccines, with the Russian one having just finished the second phase of three-step clinical trials.



Some of these vaccines require two doses three weeks apart and may confer a longer immunity.



"That might be better suited to immunise health workers in advance of an outbreak," Kieny said.



Health officials also point to the fact that other strains of the virus -- including one in Sudan -- will require the development of separate vaccines.</s>A prototype vaccine for Ebola may be "up to 100 per cent effective" in protecting against the deadly virus, the World Health Organization (WHO) said on Friday.

If all goes well, the vaccine could become available in 2018 under a fast-track approval process, it said.

In a major clinical trial, nearly 6,000 people in Guinea were given the test vaccine last year, at the tail end of a lethal epidemic of Ebola.

Not one of the 6,000 contracted the disease.

But in a control group of volunteers that did not receive the vaccine, 23 Ebola cases occurred, researchers reported in The Lancet medical journal.

"If we compare zero to 23, this strongly suggests that the vaccine is very effective, that it could be up to 100 percent effective," Marie-Paule Kieny, WHO's assistant director-general and lead author of the study, said.

Her team of three dozen researchers calculated a 90-per cent likelihood during a full-fledged epidemic that the vaccine, dubbed rVSV-ZEBOV, would work in more than 80 percent of cases.

"After 40 years, we appear to now have an effective vaccine for Ebola virus disease to build upon," Thomas Geisbert, a scientist at Galveston National Laboratory in Texas who did not take part in the study, wrote in a commentary, also in The Lancet.

First identified in 1976 in what is now the Democratic Republic of Congo, the Ebola virus erupted periodically in outbreaks of up to a couple hundred cases, mainly across west and east Africa.

In early 2014, however, a handful of infections in southern Guinea mushroomed rapidly into an epidemic.

Over the next two years, more than 28,000 people fell ill, mainly in Guinea, Liberia and Sierra Leone. Some 11,300 died.

With a mortality rate above 40 per cent, the disease -one of a category of so-called haemorrhagic fevers -- has an incubation period of up to three weeks. It causes violent and painful symptoms, including vomiting, diarrhoea, organ failure and internal bleeding.

The new vaccine was initially developed in Canada by public health authorities before being taken over by pharmaceutical giant Merck.

It is slated to be submitted by Merck to health authorities in the United States and Europe sometime next year under a fast-track approval process.

"We may have a vaccine which is registered in 2018," Kieny told journalists at a press conference Thursday, noting that the standard approval process for a new drug takes a decade, if not more.

In the meantime, Merck has committed to ensuring that 300,000 doses of the vaccine are available for emergencies under a protocol called "compassionate use".

"They will be able to produce a million in very short period of time," Kieny noted.</s>A newly developed, Ebola vaccine could bring relief to millions of people threatened by the deadly disease. Ever since the first cases of the deadly Ebola virus disease (EVD) was first detected back in 1976, there was a constant effort by drug companies and governments across the globe to develop an effective Ebola vaccine. However, until the West-African Ebola virus outbreak that ended up claiming more than 11,000 lives in the 2013-15 period, there was little progress to be seen. The most recent Ebola outbreak did however, prompt researchers to accelerate the pace of developing an effective vaccine against the deadly virus – and if we are to believe fresh reports from major publications around the world, we might be just one step away from having an effective Ebola vaccine in place. This one vaccine could potentially save thousands of lives over the next few years. While it is still pending approval from regulatory authorities around the world, there is already talk about the the possibility of a major Ebola epidemic never happening in the future, Vox reports.

It is pertinent to note here that right now, there are many potential Ebola vaccines under development. However, the one that is now making news is called the called rVSV-ZEBOV vaccine (also called VSV-EBOV). In an article on the research journal The Lancet, researchers testing the new vaccine observed that the new Ebola vaccine offered substantial protection against Ebola virus disease. The journal went on to affirm that vaccinated individuals displayed 100 percent protection from the virus. Tests on the effectiveness of rVSV-ZEBOV had been underway for the past few years. The initial results of the initial tests of the rVSV-ZEBOV Ebola vaccine were first noted last year. According to the journal, a clinical trial conducted on more than 12,000 people – mostly from countries like Guinea and Sierra Leone, among the worst affected by the outbreak back in 2013-14 indicated that the vaccine was proving to be very effective. In all, more than 5,000 people were administered the vaccine and to the researchers amazement, all of them were able to dodge the virus safely. Not a single infection was reported. Another group of individuals who were not administered the vaccine, however, reported 23 confirmed cases of the Ebola Virus Disease.

Dr. Jeremy Farrar, the director of the Wellcome Trust, commented on the startling result of the revelation termed it a remarkable outcome.

Meanwhile The New York Times reports that researchers had to adopt innovative methods to try out the new vaccine. This was because by the time the first trials for rVSV-ZEBOV was launched in 2015, the Ebola virus epidemic was also on the wane. In fact, there weren’t too many cases for them to study and deduce the effectiveness of the vaccine. That is when they tried to be creative and attempted to do something known as a “ring vaccination” in medical parlance. This method was famously used back in the 70s to eradicate Smallpox. Ring vaccination basically involves the immunization of people close to an individual who is confirmed to have contracted the disease. These close contacts may include family members, close friends, or at times, neighbors. The idea basically is to create a biological “protective ring” around these people and stop the transmission of the virus any further.

After researchers noted that the initial tests showed promising results, they changed the trial design to figure the side effects of the vaccine. The results were once again, encouraging. It was noted that most of the side effects included minor ones like headache, fatigue and muscle pain. In fact, the vaccine was even found to be safe and effective for children. To further test the vaccine, researchers also used the vaccine effectively on non-human primates where again, it was 100 percent effective in preventing an infection.

Following the success of the new Ebola vaccine, the researchers behind it are now terming it the only positive outcome from the largest ever major Ebola epidemic from 2013-15. John-Arne Røttingen, director of the division of infectious disease control at the Norwegian Institute of Public Health, who worked on the study said;

The new Ebola virus vaccine was discovered by the Public Health Agency of Canada. Now, it is under development by pharmaceutical giant Merck. The vaccine is still pending approval from agencies like the U.S. FDA (US Food and Drug Administration) At its current pace, the approval could take as long as December 2017. The delay for the final approval is most probably because of the lack of any data pertaining to the long term effectiveness of the Ebola vaccine.</s>The Ebola epidemic days may be behind us as reports state that an experimental vaccine for the deadly disease has proved to be almost 100 percent effective against the contagious infection.

The success of the vaccine is a major milestone in the scientific research and can stop any future outbreaks of the disease. The Ebola epidemic, which started in December 2013 in Guinea, was termed the deadliest ever and majorly affected the lives of people in West African countries of Nigeria, Liberia, Sierra Leone and Guinea.

Reports state that although the vaccine has not yet been approved by any regulatory authority, it is considered so effective that the researchers have already created an emergency stockpile of around 300,000 doses of it to use in any future flare-up of the disease which killed thousands of people in West Africa.

Ever since Ebola was discovered in the former Zaire in 1976, researchers have been trying to formulate an effective vaccine with little success. The sense of urgency of coming up with vaccine usually dissipated due to lack of funding over the years. However, after Ebola struck Africa in 2013 and killed around 11,000 people in the most horrific ways, the urgency was renewed and the researchers set to work again with global funding for the vaccine.

This is the first vaccine which has proved to work so well. It was said to be so effective that the testing was stopped early when the interim results of its effectiveness came out. The vaccine has been developed by the Canadian government and is now licensed to the U.S.-based Merck & Co. Merck.

Ebola is a viral hemorrhagic fever transmitted by the Ebola viruses. The virus spreads by direct contact with body fluids of an infected person or an animal. It has killed over 11,000 people globally since its outbreak in December 2013 and affected over 28,000 people.</s>PARIS: A prototype vaccine for Ebola may be “up to 100 percent effective” in protecting against the deadly virus, the World Health Organization (WHO) said Friday.

If all goes well, the vaccine could become available in 2018 under a fast-track approval process, it said.

In a major clinical trial, nearly 6,000 people in Guinea were given the test vaccine last year, at the tail end of a lethal epidemic of Ebola.

Not one of the 6,000 contracted the disease.

But in a control group of volunteers that did not receive the vaccine, 23 Ebola cases occurred, researchers reported in The Lancet medical journal.

“If we compare zero to 23, this strongly suggests that the vaccine is very effective, that it could be up to 100 percent effective,” Marie-Paule Kieny, WHO’s assistant director-general and lead author of the study, told AFP.

Her team of three dozen researchers calculated a 90-percent likelihood during a full-fledged epidemic that the vaccine, dubbed rVSV-ZEBOV, would work in more than 80 percent of cases.

“After 40 years, we appear to now have an effective vaccine for Ebola virus disease to build upon,” Thomas Geisbert, a scientist at Galveston National Laboratory in Texas who did not take part in the study, wrote in a commentary, also in The Lancet.</s>London: In a major milestone in the fight against future Ebola outbreak, an experimental vaccine has been found to be highly protective against the deadly virus, as per results of the final trial led by the World Health Organisation (WHO).

The vaccine is the first to prevent infection from one of the most lethal known pathogens, according to the results published in The Lancet journal.

"While these compelling results come too late for those who lost their lives during West Africa's Ebola epidemic, they show that when the next Ebola outbreak hits, we will not be defenceless," said Marie-Paule Kieny, WHO's Assistant Director-General for Health Systems and Innovation, and the study's lead author.

In the most recent Ebola outbreak in West Africa that started in late 2013, more than 11,000 people lost their lives. The WHO removed the global emergency tag for the disease early this year.

The vaccine, called rVSV-ZEBOV, was studied in a trial involving 11,841 people in Guinea during 2015.

Among the 5,837 people who received the vaccine, no Ebola cases were recorded 10 days or more after vaccination.

In comparison, there were 23 cases 10 days or more after vaccination among those who did not receive the vaccine.

The trial was led by the World Health Organization, together with Guinea's Ministry of Health and other international partners.

The vaccine's manufacturer, Merck, Sharpe & Dohme, this year received Breakthrough Therapy Designation from the United States Food and Drug Administration and PRIME status from the European Medicines Agency, enabling faster regulatory review of the vaccine once it is submitted.

The vaccine works by replacing a gene from a harmless virus known as vesicular stomatitis virus (VSV) with a gene encoding an Ebola virus surface protein. The vaccine does not contain any live Ebola virus.

Earlier trials had shown the vaccine to be protective in animals, and be safe and produce an immune response in humans.

Since Ebola virus was first identified in 1976, sporadic outbreaks have been reported in Africa.

But the 2013-2016 West African Ebola outbreak, which resulted in more than 11,000 deaths, highlighted the need for a vaccine.

The trial took place in the coastal region of Basse-Guinee, the area of Guinea still experiencing new Ebola cases when the trial started in 2015.

To assess safety, people who received the vaccine were observed for 30 minutes after vaccination, and at repeated home visits up to 12 weeks later.

Approximately half reported mild symptoms soon after vaccination, including headache, fatigue and muscle pain but recovered within days without long-term effects.

Two serious adverse events were judged to be related to vaccination (a febrile reaction and one anaphylaxis) and one was judged to be possibly related (influenza-like illness).

All three recovered without any long term effects, the study reported.</s>Thus far, 2016 has been a year characterized by pain, suffering, and profound disappointment for many people in many places. But maybe here at the end of the year the world is getting a wonderful Christmas gift that holds out hope for better things to come.

Yesterday the journal Lancet reported that an experimental vaccine proved 100% effective in preventing Ebola in a large trial conducted in Guinea in 2015. The vaccine is not a final solution for Ebola but it shows every promise of being a very strong first line of defense against further outbreaks of the disease.

The trial involved 11,841 people who were exposed to Ebola during the last days of the West African Ebola outbreak that claimed over 11,000 lives from 2014 to 2016. None of the 5,837 people who received the vaccine developed Ebola 10 days or more after they were vaccinated. There were 10 cases of Ebola among the people who did not receive the vaccine.

Approximately half of the people who received the vaccine reported mild adverse effects, such as headache, muscle pain and fatigue, which cleared up after a few days. Two people experienced more serious but non-fatal reactions.

The trial used a ring vaccination protocol that had been shown to be effective in eliminating smallpox. The protocol involves identifying and vaccinating people who have come into contact with someone who has an infectious disease. The idea is that the people who have been vaccinated form a ring around the infected person that prevents the disease from spreading.

In the Ebola trial, the vaccine was randomly given to about half of the adults over 18 who had come into contact with an Ebola victim with the rest scheduled to receive the vaccine three weeks later. However, everyone over six years of age was offered the vaccine immediately when it became clear that the vaccine was highly effective.

The vaccine, called rVSV-ZEBOV, was developed ten years ago by the Public Health Agency of Canada in conjunction with the United States Army. It was engineered by splicing a protein from the Ebola virus into a vesicular stomatitis virus (VSV) that infects cattle and is commonly used in lab studies. The VSV either has no effect on humans or elicits flu-like symptoms such as the headaches and muscle pains experienced by half of the people who received the vaccine. The Ebola protein triggers the production of antibodies.

The trial was carried out by the World Health Organization (WHO) and Guinea's Ministry of Health with support from the Wellcome Trust, Médecins Sans Frontières, and other organizations from Norway and Canada. The vaccine is currently licensed to Merck which was given $5 million by GAVI, The Vaccine Alliance to produce 300,000 doses of rVSV-ZEBOV for emergency use while the vaccine is going through the WHO’s approval process.

The West African Ebola outbreak was caused by Ebola-Zaire, the most common of five known variants of the virus. It is unknown whether rVSV-ZEBOV can be modified to provide protection against the different strains of Ebola. Moreover, the high rate of flu-like side effects with rVSV-ZEBOV make it unsuitable for use as a general-purpose vaccine.

More work needs to be done, but rVSV-ZEBOV is a major breakthrough in the fight to control and possibly eradicate Ebola. This year has been dark, but in these days before Christmas the light of hope for a better future shines forth.</s>“After 40 years, we appear to now have an effective vaccine for Ebola virus disease to build upon,” Thomas Geisbert, a scientist at Galveston National Laboratory in Texas, wrote in a commentary, also in The Lancet.

If all goes well, the vaccine could become available in 2018 under a fast-track approval process, WHO said.

In a major clinical trial, nearly 6,000 people in Guinea were given the test vaccine last year, at the tail end of a lethal epidemic of Ebola.

Not one of the 6,000 contracted the disease.

But in a control group of volunteers that did not receive the vaccine, 23 Ebola cases occurred, researchers reported in The Lancet medical journal.

“If we compare zero to 23, this strongly suggests that the vaccine is very effective, that it could be up to 100 percent effective,” Marie-Paule Kieny, WHO’s assistant director-general and lead author of the study, told AFP.

Her team of three dozen researchers calculated a 90-percent likelihood during a full-fledged epidemic that the vaccine, dubbed rVSV-ZEBOV, would work in more than 80 percent of cases.

First identified in 1976 in what is now the Democratic Republic of Congo, the Ebola virus erupted periodically in outbreaks of up to a couple hundred cases, mainly across west and east Africa.

In early 2014, however, a handful of infections in southern Guinea mushroomed rapidly into an epidemic.

Over the next two years, more than 28,000 people fell ill, mainly in Guinea, Liberia and Sierra Leone. Some 11,300 died.

20 cases was reported in Nigeria in 2014, 8 infected persons died, while 12 survived following the isolation of the first case, the government moved swiftly to approve a special intervention plan to contain and prevent the spread of the Ebola outbreak. The plan was propped up with the release of USD $11.5 million to support implementation.

With a mortality rate above 40 percent, the disease - one of a category of so-called haemorrhagic fevers - has an incubation period of up to three weeks. It causes violent and painful symptoms, including vomiting, diarrhoea, organ failure and internal bleeding.

The new vaccine was initially developed in Canada by public health authorities before being taken over by pharmaceutical giant Merck.

It is slated to be submitted by Merck to health authorities in the United States and Europe sometime next year under a fast-track approval process.

“We may have a vaccine which is registered in 2018,” Kieny told journalists at a press conference Thursday, noting that the standard approval process for a new drug takes a decade, if not more.

In the meantime, Merck has committed to ensuring that 300,000 doses of the vaccine are available for emergencies under a protocol called “compassionate use”.

“They will be able to produce a million in very short period of time,” Kieny noted.

Unanswered questions

There are still questions to be resolved concerning the vaccine, including side effects.

Initial tests last year did not include children, while the most recent trials covered those over six years old.

Of the more than 6,000 people injected with the Ebola vaccine only two showed serious adverse effects, the study reported. Both recovered fully.

But it is still unknown if the vaccine is safe for children six and under, pregnant women, or people with the AIDS virus - all groups that were excluded from the most recent trials.

Another unknown is how long innoculation lasts.

“With the Canadian Merck vaccine, you have a protection very early after vaccination, but we don’t know if it will last after six months,” Kieny said.

Other Ebola vaccines under development - some of which have been tested in humans - could prove more effective over a longer period.
A vaccine for the ebola virus is discovered to be 99.78%–99.87% effective.