WHO Prequalifies Merck's Ebola Vaccine, J&J Vaccine to Deploy Thursday

The World Health Organization (WHO) has prequalified Merck’s Ebola vaccine. This will accelerate the licensing, access, and roll-out in countries that are at increased risk for Ebola outbreaks.

Prequalification status indicates that the vaccine meets the WHO’s standard for efficacy, safety, and quality. Under this recommendation, the United Nations agencies and Gavi, the vaccine alliance, can access the vaccine for nations who are at risk.

The vaccine, rVSV-ZEBOV-GP (Ervebo), has been shown to be effective in preventing the Ebola Zaire virus in clinical research. Earlier this week, the European Commission granted a conditional marketing authorization for the vaccine following a recommendation for the European Medicines Agency (EMA).

“This is a historic step towards ensuring the people who most need it are able to access this life-saving vaccine," said Tedros Adhanom Ghebreyesus, PhD, director general of the WHO. "Five years ago, we had no vaccine and no therapeutics for Ebola. With a prequalified vaccine and experimental therapeutics, Ebola is now preventable and treatable."

According to a statement issued by the WHO, this is the fastest vaccine pre-qualification process conducted by the agency to date. This quick decision was made due to the urgent need for a prequalified vaccine and, to speed up the process, safety and efficacy data were monitored as it became available.

“The decision is a step towards greater availability of the vaccine in the future, though licensed doses will only be available mid-2020,” the statement notes.

The WHO will facilitate licensing of the vaccine for use in at-risk countries. With the support of the EMA, the WHO has worked closely with African regulators who have indicated that they will rapidly license the vaccine following the announcement of the WHO’s recommendation.

Earlier this year the US Food and Drug Administration (FDA) accepted a biologic license application for the Ebola vaccine and granted priority review status. The Prescription Drug User Fee Act, or target action date, is set for March 14, 2020.

The rVSV-ZEBOV vaccine has been deployed for use in the ongoing Ebola outbreak in the Democratic Republic of the Congo (DRC) since August 2018. Since administration began, 250,622 individuals have been vaccinated. As of November 11, 2019, there have been 3169 confirmed cases of Ebola documented with 2075 confirmed deaths.

On Tuesday, November 12, DRC response coordinators and international affiliates met with representative from Doctors Without Borders to discuss the implementation of Johnson & Johnson’s Ebola vaccine, Ad26.Zebov, into the outbreak response.

The new vaccine will be implemented on Thursday, November 14, in 2 health districts, Majengo and Kaheme. The vaccine will be administered intramuscularly in 2 doses, 56 days apart.

According to the DRC Ministry of Health the vaccine has a strong immune response and targets adults and children over the age of 12 months. The vaccine was authorized for use in September, after the WHO’s Strategic Advisory Group of Experts on Immunization indicated that a second vaccine would create “more opportunities to vaccinate hard-to-read individuals, and increasing the number of people vaccinated within communities with ongoing transmission.”

For the most recent case counts in the Ebola outbreak in the DRC, check out the Contagion® Outbreak Monitor.