The controversial kind of study is called a “human challenge study” and it’s controversial because it involves researchers purposefully infecting (or “challenging”) healthy volunteers with the virus after giving them an experimental treatment or vaccine, to see if it worked.
Phase 3 trials are the standard route for evaluating experimental vaccines and treatments. In those, researchers give a candidate drug to thousands of volunteers and then follow them to see how many end up developing the disease from exposure to it in everyday life. This route requires a lot of participants and also requires the virus to continue circulating widely in order to work.
In July, scientists with the National Institutes of Health, of which NIAID is a part, wrote in the New England Journal of Medicine that phase 3 clinical trials remain the most efficient route for developing a vaccine against COVID-19, in addition to being most reflective of real-life conditions. Still, they suggested stockpiling SARS-CoV-2 (and other coronaviruses, too), ideally with mutations that weaken the virus, just in case they’re needed down the road.
In August, Dr. Anthony Fauci reiterated the plan to stick with the standard route, telling the Washington Post that human challenge studies were not a Plan B option, but instead a “Plan C or Plan D” option.
First reported by the Financial Times, NIAID has signed a contract with Colorado State University to provide two strains of the virus for potential human challenge studies. (Technically, it’s BioMARC, a non-profit owned and operated by CSU).
Ray Goodrich, director of the Infectious Disease Research Center at CSU, said one strain was isolated from a Washington patient and the other from a New York patient.
“This is something that you can't turn on a switch and it's done. It will take months in order to produce this material,” he said.
The most likely scenario in which human challenge studies would seem necessary is if the virus stopped circulating widely in the American public, making it less likely that phase 3 trial participants would encounter the virus, and therefore making it harder for scientists to know if their vaccine actually helped protect against it.
“It definitely is a fallback to a fallback to a fallback, but it's one of those things that you need to have in case you need it,” said Goodrich.
In a statement provided to the Mountain West News Bureau, NIAID confirmed that in August it signed a $3.6 million contract with BioMARC to manufacture the strains, and that “no other such contracts have been awarded by NIAID.”
“NIAID anticipates that, toward the end of 2020, preliminary (and potentially final) data from SARS-CoV-2 candidate vaccine clinical trials will be available and will be used to assess future SARS-CoV-2 human challenge studies, should they be needed and deemed safe and ethical to employ,” the statement read.
Goodrich and his colleagues had already been growing SARS-CoV-2 for their work on a potential vaccine, currently being tested in animals. He noted that the facility where the virus is grown is one of 14 laboratories across the country that was set up, with NIH funding, to help in infectious disease emergencies.
“So, it's not surprising that this was one of the sites that the NIH looked at as a possible location for manufacturing this type of material,” he said.
According to the Financial Times, in January researchers in the U.K. plan to begin human challenge studies, exposing healthy volunteers to the virus in an effort to speed up vaccine development. The participants would remain isolated at a research facility during the trial.
This story was produced by the Mountain West News Bureau, a collaboration between Wyoming Public Media, Boise State Public Radio in Idaho, KUNR in Nevada, the O'Connor Center for the Rocky Mountain West in Montana, KUNC in Colorado, KUNM in New Mexico, with support from affiliate stations across the region. Funding for the Mountain West News Bureau is provided in part by the Corporation for Public Broadcasting.