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NIH reports success from large Ebola vaccines clinical trial in West Africa


Results from the clinical trial in Liberia show that two candidate-Ebola vaccines pose no major safety concerns and can elicit immune responses by one month after initial vaccination

By Team ABLE

Results from a large randomized, placebo-controlled clinical trial in Liberia show that two candidate Ebola vaccines pose no major safety concerns and can elicit immune responses by one month after initial vaccination that last for at least one year. The findings, published in the October 12 issue of the New England Journal of Medicine, are based on a study of 1,500 adults that began during the West Africa Ebola outbreak. The trial is being conducted by a U.S.-Liberia clinical research collaboration known as the Partnership for Research on Ebola Virus in Liberia (PREVAIL), established in 2014 in response to the request from the Liberian Minister of Health to the U.S. Secretary of Health and Human Services.

The trial is sponsored by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH) and involves scientists and clinicians from Liberia and the United States.

“This clinical trial has yielded valuable information that is essential for the continued development of these two Ebola vaccine candidates and also demonstrates that well-designed, ethically sound clinical research can be conducted during an epidemic,” said NIAID Director Anthony S. Fauci, M.D. “A safe and effective vaccine would be a critically important addition to classical public health measures in controlling inevitable future Ebola outbreaks.”

PREVAIL conducts collaborative biomedical research in accordance with best practices, to advance science, strengthen health policy and practice, and improve the health of people in Liberia and around the world. The partnership launched this first study, PREVAIL 1, in February 2015.  Originally designed to enroll 28,000 volunteers, the trial was scaled back to a Phase 2 study when the decline in new Ebola cases made it impossible to conduct a large efficacy study.

The vaccine candidates included cAd3-EBOZ, co-developed by NIAID’s Vaccine Research Center and GlaxoSmithKline (GSK); and rVSV-ZEBOV, which was initially engineered by scientists from the Public Health Agency of Canada and is now licensed to Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc., (Merck). GSK and Merck provided the test vaccines for the study.