Finally: Merck Ebola vax triumphs in phase III trial, overcoming logistical nightmare
- Merck's investigational Ebola vaccine, rVSV-ZEBOV, has been found to be 100% effective in protecting patients against the virus, according to an interim analysis of phase III trials in West Africa. Merck's vaccine—licensed from NewLink Genetics and the Public Health Agency of Canada—utilizes a rabies-like virus that has been modified to include an Ebola virus gene. The full interim analysis will be posted on The Lancet on Friday.
- A single dose of the vaccine was able to effectively protect patients within six to 10 days of its administration in a large-scale, WHO-sponsored ring vaccination trial involving more than 4,000 participants. This is a rigorous—and logistically speaking, exceedingly difficult-to-implement—trial method that involves identifying recently infected patients and several degrees of their contacts and then immunizing all of the relevant parties. As The Lancet notes, this was the same vaccination method used to eradicate small pox.
- Public health officials are cautiously optimistic that if this level of efficacy can be maintained in two other ongoing mid- and late-stage trials, the vaccine can soon be licensed and deployed, hopefully putting an end to one of the most difficult health crises of the 21st century. "If proven effective, this is going to be a game changer, and it will change the management of the current Ebola outbreak and future outbreaks," said WHO director general Margaret Chan in a news conference on Friday.
Of all the critical scientific and epidemiological lessons to be gleaned from the year-long effort to combat this scourge, the most instructuve for the industry might be this: Even the most ardent public health threats can be conquered with global teamwork among regulatory organizations, public health agencies, and private medical and pharmaceutical companies. Lancet editorial board members made this exact point on Friday, and they are worth quoting in full:
"One important message goes beyond even Ebola—the power of multilateralism and inclusive partnership to devise and execute critical clinical research," wrote the authors. "Ebola has been a catastrophe for west Africa. But out of this epidemic has come the opportunity to build unprecedented collaborations to generate evidence to advance health. There have been few better examples to prove the value and importance of WHO to strengthen global health security."
Agencies and companies combating Ebola have faced myriad problems including, ironically enough, the fact that the epidemic has been steadily waning in the region. That's led to a dearth of potential trial participants, which makes the success of the ring vaccination trial all the more impressive for both the study leaders and the patients who made such a design possible in the first place.
Now for the caveats: We still have to wait and see whether or not this vaccine is effective over the long-term, or whether it only provides short-term protection. And it's always possible that the other ongoing trials won't elicit results that are quite as glowing. But for now, it appears that there's a new standard of hope in West Africa.
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