First Ebola Vaccine Gains Full EU Approval, WHO Prequalification
Sun, January 23, 2022

First Ebola Vaccine Gains Full EU Approval, WHO Prequalification

Ervebo is the first of its kind to help control deadly Ebola outbreaks. / Photo by: Tobias Arhelger via 123rf


For the first time, an Ebola vaccine for human use has been fully approved.

The European Commission granted the vaccine, named Ervebo, full marketing authorization in Europe following its recommended approval in mid-October from the European Medicines Agency (EMA).

Ervebo is the first of its kind to help control deadly Ebola outbreaks and, with the recent approval, will be distributed more widely than it is now. This is important considering that the virus has a high fatality rate.

“This is a vaccine with huge potential. It has already been used to protect more than 250,000 people in the DRC and could well make major Ebola outbreaks a thing of the past,” said Seth Berkley, chief executive of Gavi, the public-private global health partnership committed to increasing access to immunization in poor countries.

The First of Its Kind

US pharmaceutical company Merck will be marketing the vaccine. There are several vaccines used against Ebola, but Ervebo is the first—and currently, the only—one tested during an outbreak.

The recently approved vaccine was used to address the ongoing outbreak in the Democratic Republic of Congo (DRC) where Ebola has killed about 2,000 people since last year and showed to be highly effective in preventing infection.

Since the Ebola vaccination in the DRC last year, Ervebo has been used to vaccinate about 164,000 persons. As of June 2019, another 500,000 vaccine doses are available—and 200,000 more are currently in production, according to Precision Vaccinations.

Precision Vaccinations is an international publisher of research-based vaccine news that provides accurate information on vaccine news based on fact-checked data and information.

It adds that a recent analysis of the Ebola vaccine showed an estimated efficacy of 97.5 percent. That high efficacy rate led the DRC’s Health Minister to call for a full license of Merck’s vaccine.

With the full approval of European regulators, Ervebo will now reach wider populations—especially in low-income economies like DRC, which now has the largest-ever Ebola outbreak after surpassing 3,000 cases last year, as per figures from the country’s Health Ministry.

Since its testing, Everbo has been used for a strategy known as ring vaccination. It’s where health workers inject vaccines to those who are most likely to be infected with a disease to prevent more people from being infected.

Planning for Protection

While it’s been proven effective when applied in outbreaks, it’s also important to know if the vaccine could also be used in other ways—including preventive administration to health workers who may encounter Ebola in the future.

This means researchers would have to determine the duration of the vaccine’s protection and if an additional dose can extend immunity, weekly scientific journal Nature says. It notes Oxford vaccinologist Adrian Hill saying that these studies are currently in the works both with Everbo and other competing vaccines.

“The question remains, which vaccine would you give to, say, health-care workers to prevent them [from] getting Ebola?” Hill said.

Merck’s vaccine provides protection against the Zaire species of the Ebola virus, which caused the current DRC outbreak and the West African outbreak in 2014-2016. The vaccinologist emphasized the importance of developing vaccines against other Ebola species as well, especially the Sudan species that triggered seven outbreaks since 1976.

David Heymann, an epidemiologist at the London School of Hygiene and Tropical Medicine, also stressed the need for more research into Everbo and the continuation of other developments.

“The message is that the research is not done. It must continue,” Heymann told Nature. “It’s really important to continue to study vaccines and develop those second- and third-generation vaccines.”

These further studies may help provide longer-lasting immunity, targeting more than one Ebola strain, and allow easier storage.


Merck’s vaccine provides protection against the Zaire species of the Ebola virus, which caused the current DRC outbreak and the West African outbreak in 2014-2016. / Photo by: Sebastian Kaulitzki via 123rf


WHO Grants Prequalification

Aside from the European Commission’s marketing authorization, the WHO also prequalified Everbo in a key milestone that will help boost its licensing, access, and distribution in high-risk countries. Being granted with prequalification means the vaccine met the international agency’s standards for quality, safety, and efficacy.

It’s the fastest vaccine prequalification process that the WHO conducted in its history and came from the urgent public health need to provide a prequalified Ebola vaccine for the ongoing outbreak of the disease.

“This is a historic step towards ensuring the people who most need it are able to access this life-saving vaccine,” WHO Director-General Tedros Adhanom Ghebreyesus said in a press release.

“The development, study, and rapid prequalification of this vaccine show what the global community can do when we prioritize the health needs of vulnerable people.”

Ghebreyesus also said that with a prequalified vaccine and experimental therapeutics, Ebola has now become preventable and treatable.

Unlike other infectious diseases like influenza or tuberculosis, Forbes says Ebola wasn’t given much awareness and earlier attempts at developing a vaccine didn’t get much support. That is until the 2014-2016 outbreak in West Africa that made international headlines.

Since then, the world began to wonder and worry about the deadly disease and began to call for action to prevent it from spreading. The early patent for the vaccine, conducted by researchers at the Public Health Agency of Canada’s National Microbiology Laboratory, was taken over by Merck until it developed what is now known, approved, and prequalified as the Ebola vaccine: Everbo.