The trial, led by the World Health Organization in conjunction with other local and global groups, examined the efficacy or the rVSV-ZEBOV vaccine. Efforts were ramped up after the infectious disease caused a major outbreak, beginning in 2013 in Guinea and spreading to Liberia and Sierra Leone. By comparison, 23 new cases were reported among those who did not receive the vaccination.
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There are now no formal recommendations on when to use the experimental Ebola vaccine. A number of other vaccines – developed by GlaxoSmithKline and the Beijing Institute of Biotechnology, among other groups – also have shown promise and are advancing in human trials.
Findings from tests of rVSV-ZEBOV, a trial vaccine, show a 100% protection rate with thousands of people tested in Guinea all confirmed as virus-free within 10 days. So the researchers had to be creative. Researchers used a “ring vaccination” method, wherein vaccinations were given to family, friends, neighbors, and caregivers if a victim developed the disease.
And once it was administered, they would approach the people living closest to the patient, making a shape of cluster or ring, averaging around 80 people. When a patient was diagnosed with Ebola, the research team traced all people who may have been in contact with the individual in the last three weeks.
Many diseases which are vaccine curable, such as yellow fever and polio, have persisted for decades despite the availability of an affordable vaccine. “Adverse events data indicated no safety concerns in adults or children”, the researchers concluded.
For the first time ever a vaccine has been created that can prevent infection from one of the most deadly viruses on the planet.
The WHO’s Marie-Paule Kieny said the results could help combat future outbreaks.
The trial was conducted on 11,841 citizens of Guinea this week.
The “ring vaccination” technique also had a positive impact on public health impact: communities of those who were vaccinated were also less likely to get sick. And it is now being further manufactured by Merck, which is one the of the largest pharmaceutical companies in the world.
The reports said as part of this agreement, Merck committed to ensuring that 300,000 doses of the vaccine are available for emergency use in the interim, and to submit the vaccine for licensure by the end of 2017.
And questions about the vaccine’s long-term effectiveness remain.
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“Protective efficacy is clearly the strength of the study”, Thomas Geisbert, a microbiology professor at the University of Texas Medical Branch, wrote in a journal commentary published alongside the study. However, everyone over six years of age was offered the vaccine immediately when it became clear that the vaccine was highly effective.
