LONDON – The British government says it may take part in a study that tries to deliberately infect volunteers who have been given an experimental vaccine against the coronavirus in an effort to more quickly determine if the vaccine works.
The approach, called a challenge study, is risky but proponents think it may produce results faster than typical studies, which wait to see if volunteers who have been given an experimental treatment or a dummy version get sick.
“We are working with partners to understand how we might collaborate on the potential development of a COVID-19 vaccine through human challenge studies,” the U.K. Department for Business, Enterprise and Industrial Strategy said in a prepared statement. “These discussions are part of our work to research ways of treating, limiting and hopefully preventing the virus so we can end the pandemic sooner.”
Challenge studies are typically used to test vaccines against mild diseases to avoid exposing volunteers to a serious illness if the vaccine doesn't work. While the coronavirus causes only mild or moderate symptoms in most people and seems to be especially mild in young, healthy people, the long-term effects of the disease aren't well understood, and there have been reports of lingering problems in the heart and other organs even in those who don't ever feel sick.
In the U.S., the National Institutes of Health has downplayed the need for challenge studies given the speed with which vaccines are being developed, but said Thursday it is taking some preliminary steps in case the more controversial approach eventually is required. Those preliminary steps include examining the ethics of a challenge study, and funding research to create lab-grown virus strains that potentially could be used.
But even if needed, “human challenge trials would not replace Phase 3 trials” of COVID-19 vaccines, according to a statement from NIH that called the standard, rigorous studies its priority.
Tens of thousands of volunteers have already signed up around the world to test leading candidates and the coronavirus still is spreading widely enough in many locations that manufacturers are confident of answers by year’s end about at least some of the shots.
In July, the NIH’s vaccine working group published a paper in The New England Journal of Medicine pointing out the risks of doing a challenge study with a virus that so far has no good treatment and is wildly unpredictable, occasionally killing even some young, otherwise healthy people.