An Effective Ebola Vaccine Has Been Developed

Following a horrific epidemic in West Africa that claimed the lives of over 11,000 people — the deadliest the world had ever seen — we finally have a breakthrough vaccine against Ebola. As reported:

Today, the same researchers — who hail from the World Health Organization, Guinea’s Ministry of Health, Public Health England, and other international partners — have unveiled their final results in the Lancet, and they’re just as remarkable. The vaccine was tested in a trial involving nearly 12,000 people in Guinea and Sierra Leone during 2015 and 2016. Among the 5,837 people who got the vaccine, no Ebola cases were recorded. By comparison, there were 23 Ebola cases in the control group that had not gotten the vaccine.

“This trial, confirming the 100 percent efficacy of the rVSV Ebola vaccine, is a simply remarkable outcome”, Dr. Jeremy Farrar, the director of the Wellcome Trust, said of the research. “We’ve shown that by working collaboratively, across international borders and sectors, we can develop and test vaccines rapidly and use them to help bring epidemics to an end”.

You can read the published study here. It was one of fifteen clinical trials for an Ebola vaccine conducted around the world in a single year, and is a vindication of what collective action and responsibility by the international community — including the U.N., NGOs, and national governments — can accomplish. It is a shame it took so many deaths spanning a nearly three year period to finally come up with a promising form of prevention, although the vaccine is far from ready to hit the market. 

The vaccine was discovered by the Public Health Agency of Canada and is now under development by the drug company Merck. For now, Merck is doing additional safety studies on children and other vulnerable populations and will be seeking approval from a regulator like the US Food and Drug Administration by the end of next year. In case of an emergency, the company has committed to ensuring that 300,000 doses of the vaccine are available, so the vaccine won’t hit the market just yet.

In addition to proving the value of global cooperation, the vaccine successfully demonstrated an approach to clinical trials that had previously helped eradicate another public health scourge:

When they launched the trial in 2015, the number of Ebola cases in Guinea had already declined, and there were too few cases to run a meaningful traditional randomized study (giving the vaccine to a randomly selected group and comparing it with a control group that doesn’t get the vaccine). So the researchers had to be creative. They decided to try something called “ring vaccination,” a public health method used to eradicate smallpox in the 1970s. It involves immunizing the immediate contacts — friends, family, housemates, neighbors — of a person who falls ill with a virus to create a protective ring around them to stop transmission.

As soon as a new Ebola case was diagnosed, the researchers traced all their contacts for a total of 117 clusters (or “rings”), each made up of about 80 people. They then randomized the rings of people to get the vaccine either right after their friend or family member had been diagnosed or after a three-week delay.

Their preliminary results were so positive that the researchers changed the trial design so that everyone got the vaccine immediately, including children. A little more than half of those vaccinated (3,149 people) reported at least one side effect, but they were mostly mild (headache, fatigue, and muscle pain). Eighty serious adverse events were reported, but only two (a fever and an allergic reaction) were deemed to be related to the vaccine. “Adverse events data indicated no safety concerns in adults or children,” the researchers concluded.

What an incredible achievement to come out of such a dark chapter in the history of public health. Of course, there are still questions about the long-term efficacy of the vaccine, as well as practical concerns regarding how and whether it will be administered; as it is, so many people die from perfectly preventable causes due to lack of access to health care resources. It is one thing to develop a cure or treatment, but a totally different matter to make sure it actually makes it out to vulnerable populations.

The impressively rapid, yet belatedly started, search for a vaccine to this long-known disease has also raised questions about how the world should plan and prepare for other deadly potential epidemics.

There’s also the question of how to speed up the development of vaccines for deadly viruses like Ebola, which may seem like distant threats — until it’s too late. The virus was discovered in 1976 but mainly affected people in Africa until the 2014 outbreak in West Africa, which affected more than 28,000 people and killed more than 11,000. The Department of Defense and other funders only started to pour money into Ebola vaccine development when the virus was deemed a biological weapon after the 9/11 terrorist attacks.

“Had a vaccine been available earlier in the Ebola epidemic, thousands of lives might have been saved”, Farrar added. “We have to get ahead of the curve and make promising diagnostics, drugs, and vaccines for diseases we know could be a threat in the future”. Farrar hopes this success story will inspire stakeholders to prepare for future potential epidemics — an important message at a time when the likelihood of global outbreaks is only accelerating.

The world has demonstrated, however late, that it is capable of coordinated a concerted and effective response to issues that transcend borders: this vaccine was first discovered by Canada’s Public Health Agency and developed by an American pharmaceutical company, Merck, as part of an international effort led and funded by the U.N. World Health Organization, with support from the London-based Wellcome Trust (the world’s second largest private biomedical research funder), Medecins Sans Frontieres (a.k.a. Doctors Without Borders), and the Norwegian and Canadian governments. The Ministry of Health for Guinea, which was among the hardest hit by the most recent Ebola outbreak, helped administer the clinical trial. Researchers from all over the world took part. This is an important example of the effectiveness and necessity of a concerted global response to global problems, even if it came belatedly and still has a long way to go. 

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