Ebola Vaccine Approved by FDA

The US Food and Drug Administration (FDA) has announced that the Ebola vaccine Ervebo has been approved for administration in individuals 18 years of age and older. This is the first vaccine for the prevention of Ebola virus disease that has been authorized in the United States. The approval was granted to Merck & Co., Inc.

Ervebo is administered as a single-dose injection and is a live, attenuated vaccine.

“While the risk of Ebola virus disease in the US remains low, the US government remains deeply committed to fighting devastating Ebola outbreaks in Africa, including the current outbreak in the Democratic Republic of the Congo,” said Anna Abram, FDA Deputy Commissioner for Policy, Legislation, and International Affairs in the FDA's statement.

The vaccine was used as an investigational vaccine in the Democratic Republic of the Congo where the second largest Ebola outbreak is ongoing. The vaccine was authorized by the World Health Organization under an expanded access program to help mitigate the outbreak.

According to the FDA, the approval was supported by a study conducted in Guinea during the 2014-16 Ebola outbreak. The study was a ring vaccination study in which 3537 contacts, and contacts of contacts, of individuals with Ebola received either immediate vaccination or delayed vaccination 21 days after exposure.

In a comparison of among 2108 individuals in the immediate vaccination arm and 1429 individuals in the delayed vaccination arm, the vaccine was found to be 100% effective in preventing Ebola cases with symptom onset greater than 10 days after vaccination. In the study 0 cases of Ebola with symptom onset greater than 10 days after vaccination were observed in the immediate cluster group; 10 cases were observed in the 21-day delayed group.

The vaccine was also assessed in additional studies including in 477 individuals in Liberia, approximately 500 individuals in Sierra Leone and approximately 900 individuals in Canada, Spain and the United States. The antibody responses among those in the study conducted in Canada, Spain and the United States were similar to those among individuals in the studies conducted in Liberia and Sierra Leone.

In total, the safety of Ervebo was assessed in approximately 15,000 individuals. The most commonly reported side effects were pain, swelling and injection site redness, as well as headache, fever, joint and muscle aches and fatigue.

The FDA granted the vaccine priority review and a tropical disease priority review voucher. The FDA also granted breakthrough therapy designation for Ervebo. Because of the public health importance of a vaccine to prevent Ebola, the FDA worked closely with the company and completed its evaluation of the safety and effectiveness of Ervebo in less than 6 months.

“Ebola virus disease is a rare but severe and often deadly disease that knows no borders. Vaccination is essential to help prevent outbreaks and to stop the Ebola virus from spreading when outbreaks do occur,” Peter Marks, MD, PhD, director of the FDA’s Center for Biologics Evaluation and Research, said in the statement.

“The FDA’s approval of Ervebo is a major advance in helping to protect against the Zaire ebolavirus as well as advancing U.S. government preparedness efforts. The research approach used to study the effectiveness and safety of this vaccine was precedent-setting during a public health emergency and may help create a model for future studies under similar circumstances. The FDA is committed to continuing our work across the US government and with our international partners to prevent future Ebola outbreaks and mitigate the current outbreak in the DRC, reflecting our nation’s commitment to preparing for and responding to biological threats, like Ebola.”