European researchers said Friday that an experimental Ebola
vaccine tested in Guinea "might be effective" in protecting people
from the deadly virus, but behind the scenes, questions have been
raised over the way the study was conducted.
The vaccine, from Merck & Co. and NewLink Genetics Corp. and
dubbed VSV-ZEBOV, is one of a handful of vaccines and drugs that
were rushed into bigger studies after a massive Ebola outbreak hit
West Africa last year. About 27,780 people have been infected and
about 11,290 have died, according to the World Health Organization
(http://apps.who.int/ebola/ebola-situation-reports).
In the Guinea trial, 4,123 people were assigned to immediate
vaccination, and 3,528 were assigned to delayed vaccination.
The results, published in The Lancet, suggest the vaccine may be
highly effective, with no patients getting sick who immediately got
the vaccine; by contrast, 16 people got sick in the control group
of people who were vaccinated 21 days after exposure.
People familiar with the issue said the U.S. Food and Drug
Administration has prepared a critical commentary about the study,
but that The Lancet, the British journal that is making the study
public online Friday, declined to publish the commentary
simultaneously.
Also, U.S. officials said that the researchers changed the
protocol during the trial—generally a troublesome step—by deciding
to measure cases only after a 10-day cutoff. The European
researchers weren't immediately available to comment.
Mark Feinberg, chief public health and scientific officer for
Merck said, that "the hope was a vaccine might be developed in
sufficient time to have an impact to help control and maybe help
eliminate this Ebola outbreak if it were to persist." He added,
"The study did provide strong evidence supporting vaccine efficacy.
Whether this evidence by itself will be seen by all stakeholders as
definitive will be an important discussion.
Write to Thomas M. Burton at tom.burton@wsj.com and Peter Loftus
at peter.loftus@wsj.com
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