The Most Promising Ebola Vaccine Has Been Sitting on the Shelf for 15 Years
Fever was the first symptom to grip the crab-eating macaques in their high-containment laboratory on an island off Texas after being infected with the newly
Fever was the first symptom to grip the crab-eating macaques in their high-containment laboratory on an island off Texas after being infected with the newly discovered Bundibugyo strain of ebola. Then came the weight loss, the rectal bleeding and nosebleeds, while scientists in space suits drew blood to see how the monkeys’ immune systems struggled to fight the aggressive virus. But the three monkeys that had received a newly developed vaccine to protect against the understudied strain showed no symptoms of the disease, which eventually killed two-thirds of their unvaccinated companions. It was 2011, and virologist Thomas Geisbert’s work developing the vaccine was done. If the vaccine had protected primates from the Bundibugyo strain of ebola, it was highly likely to protect humans. Yet with an outbreak now raging in the Democratic Republic of Congo and Uganda, Geisbert’s promising vaccine hasn’t been deployed at all—or even put through human trials—because there hasn’t been the funding or interest.
And it could take months to test its safety and efficacy, even as the Bundibugyo virus causes widespread suffering. “We’ve got the rVSV Bundibugyo vaccine sitting on the shelf,” says Geisbert, an immunology professor at the University of Texas Medical Branch in Galveston. Recombinant vesicular stomatitis virus “rVSV” vaccines use a harmless version of that virus to deliver the genetic instructions needed for the body to fight the disease. Hundreds of people have been infected in the current outbreak in Central and East Africa, and around 200 have died. Public health officials have been scrambling to develop a vaccine, with the World Health Organization identifying Geisbert’s as the most promising candidate. Geisbert’s work began in the early 2000s as a defense project focused on other strains of ebola. In the wake of September 11 and concerns that terrorists may deploy ebola and similar pathogens as biological weapons (something the Soviet Union had investigated during the cold war), the US Army provided funding to develop a vaccine for the virus.
His first big breakthrough in 2003 found monkeys could be protected from ebola with a single injection of the vaccine he had developed. But when Geisbert first published his findings a few years later, he found little commercial interest. “There just wasn’t a global market for an ebola vaccine,” he says. “It’s not a moneymaker, nobody really wanted to pick it up.” That in part led Geisbert to look at whether this vaccine could protect monkeys from different strains of the disease, which would make it cheaper and easier to develop and mass produce. He tested a blend of vaccines against three of the four ebola viruses known to harm humans with success and published the results in 2009. Interest in taking them beyond the lab reached a critical mass during the 2013 to 2016 ebola epidemic, when the Zaire strain—the most common—infected 28,600 people and killed 11,300 in West Africa.
The BriefWire