A public-private partnership will pay Merck & Co. $5 million to stockpile 300,000 doses of an Ebola vaccine that appeared to work in a Guinea trial last year. ScienceInsider has learned that GAVI, a Geneva, Switzerland–based organization that primarily helps poor countries vaccinate their children, plans to announce the deal Wednesday morning at the World Economic Forum in Davos, Switzerland.
In addition to making the vaccine available as of May 2016 to respond to emergencies, GAVI also wants its money to help the pharma company continue to develop the vaccine and submit it for licensing with regulatory agencies by the end of 2017. “I think it is good to reward companies for investing in this area, even if the amount is somewhat symbolic, and to get a commitment that they will move this forward,” said Marie-Paule Kieny, assistant director general at the World Health Organization (WHO) in Geneva.
Before the current West African Ebola epidemic began, the virus had caused fewer than two dozen outbreaks in nearly 4 decades, sickening about 2400 people. That made Ebola an unattractive target for vaccinemakers, especially because the disease only occurred in poor African countries. “Given that there is a market failure, we wanted to make sure that this vaccine is taken all the way,” Seth Berkley, the head of GAVI, told ScienceInsider. “We also wanted to make sure that there is vaccine available in the interim period before there is a licensed product.”
Stockpiling the vaccine is critical, says Jeremy Farrar, director of the Wellcome Trust, the London research charity that co-funded the vaccine trial in Guinea. “Ebola epidemics are inevitable,” wrote Farrar in an email, noting that there is an animal “reservoir” of the virus that will keep reintroducing it to humans. But GAVI’s contribution is especially important in light of “all the horror of the Ebola epidemic,” Farrar wrote, as “the development of this vaccine is one very positive outcome.”
Originally developed by the Public Health Agency of Canada, the vaccine contains a gene for the Ebola virus surface protein stitched into a harmless livestock pathogen, vesicular stomatitis virus (VSV). Merck licensed the vaccine at the height of the West African Ebola epidemic in 2014, and moved it through clinical testing faster than any vaccine in history. An ongoing trial in Guinea with the VSV vaccine found that it protected participants so well that the control arm of the study was abandoned after an interim analysis.
Before Merck seeks a license for the vaccine, it wants to gather more data for regulatory authorities. In the meantime, countries may want to use the vaccine to control an outbreak. Just hours after WHO announced the end of the Ebola outbreak last week, Sierra Leone reported a new death from the disease. Contacts of the 22-year-old woman at four different locations in Sierra Leone are going to be offered the vaccine, Kieny said. But as long as the vaccine has not been licensed, it can only be used as an experimental vaccine in a clinical trial, which is cumbersome. “You can’t just line people up and offer them the shot,” Kieny says. “You need to inform every single participant of the possible risks, and get their informed consent.”
In Sierra Leone, Doctors without Borders (MSF) will administer the vaccine as part of the ongoing Guinea trial, which has been extended to Sierra Leone. In its unusual “ring” design, only people who have come in contact with confirmed Ebola cases are vaccinated. But future outbreaks may occur in countries where there is no ongoing trial, which will mean the experimental product could not be used until the countries go through the extra steps of designing a study, getting ethical approval, and working through complex liability issues. “There is an absolute need for a licensed vaccine,” Kieney says. She says until the vaccine receives approval, WHO will work with MSF to conduct emergency ring vaccinations in any country in Africa affected by a new Ebola outbreak.
Berkley says GAVI’s move could also benefit companies that have other vaccine candidates in development but do not have efficacy data from a trial that took place during an outbreak. “They will need to show data from animal experiments and link it to the efficacy data in humans,” Berkley says. “So it is important for them as well to get the data from this vaccine in front of regulatory agencies as soon as possible.”