Experimental Ebola Vaccines Elicit Year-Long Immune Response

A volunteer receives an injection in the PREVAIL Ebola vaccine clinical trial in Liberia.

Photo: PREVAIL

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 1 month after initial vaccination that last for at least 1 year. The findings, published in the Oct. 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. It is sponsored by NIAID 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 Dr. Anthony Fauci. “A safe and effective vaccine would be a critically important addition to classical public health measures in controlling inevitable future Ebola outbreaks.”