There’s a new tool in the fight against Ebola in West Africa: rVSV-ZEBOV, a vaccine that has recently concluded a study phase, with researchers finding that it was incredibly effective against the deadly disease. While it’s still in trial stages, the drug appears to be a promising tool moving forward.
In a study published in The Lancet on July 31st, 2015, a team of researchers followed the effects of a vaccine trial that began in April of this year in Guinea. rVSV-ZEBOV has been in development from a Canadian company since 2011, and was tested on 7651 between 90 clusters of the disease. Individuals in 48 of the clusters were given the vaccine right away, while individuals in the other 42 clusters were given the vaccine after a delay of 21 days. In the groups given the vaccine immediately, no individuals came down with Ebola, while 16 individuals in the other side presented with the disease. The groups were randomized, with the groups equally represented among populated and rural areas.
Researchers adopted a strategy used in other infectious diseases, such as Smallpox: a ringed vaccination approach, where individuals surrounding a cluster given the vaccine over a geographical area: “Ring vaccination is defined as the vaccination of a cluster of individuals at high risk of infection, owing to their social or geographical connection to a confirmed index case.”
The trial, dubbed Ebola ça Suffit (Ebola this is enough), was designed to test whether or not the vaccine was effective in a larger population. This seems to be the case, as no cases of Ebola that likely would have occurred appeared. This is a major step forward in the fight against the disease: up until this point, aid workers have merely been managing the disease when it presents itself and keeping people hydrated and comfortable. With the amount of waste that the disease produces per person, the individuals at the most risk are healthcare workers: some of whom have come down with the disease and since died. A vaccine would be the first major step in protecting West Africa’s healthcare infrastructure from becoming a focal point of the illness.
The conclusions of the trial? “The interim results of the Ebola ça Suffit ring vaccination trial suggest that the efficacy of a single injection of rVSV-ZEBOV to prevent Ebola virus disease might be high, that protection can be established quickly, and that the vaccine might be effective at the population level when delivered by ring vaccination.” The fact that this vaccine can be distributed quickly and in a single dose is a positive sign: once it is approved, it can be deployed across the country. You can read the entire study here.
However, one thing to keep in mind: a vaccine isn’t a magic bullet, and while the early results have appeared promising, there’s still a lot of work to do before this is approved and deployed. The state of healthcare resources across West Africa helped to contribute to the rise of such a disease, and efforts to educate the public on the nature and transmission methods of Ebola are equally as crucial to bringing the illness to an end. The World Health Organization noted in a statement that “While the vaccine up to now shows 100% efficacy in individuals, more conclusive evidence is needed on its capacity to protect populations through what is called “herd immunity”. To that end, the Guinean national regulatory authority and ethics review committee have approved continuation of the trial.”
However, news of a vaccine comes at an opportune time: while the West African Ebola Outbreak has slowed down, cases are still appearing within Guinea, Libera and Sierra Leone. This drug will undoubtedly be one step forward in bringing the crisis to an end, and will hopefully help prevent comparable outbreaks from occurring in the future.
[The Lancet via NPR]
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