NIH Prepares for Possible COVID-19 Human Challenge Studies

The NIH’s National Institute of Allergy and Infectious Diseases (NIAID) is developing a weakened strain of SARS-CoV-2 for use in human challenge trials in case they’re needed to fully evaluate COVID-19 vaccine and therapeutic candidates, though the institute says the controversial studies would not replace phase 3 trials.

The NIAID is prioritizing randomized trials for vaccine candidates, but it is also weighing the ethical and technical considerations of a human challenge study model, a spokesperson said.

“Toward the end of 2020, NIAID anticipates preliminary (and potentially final) data from SARS-CoV-2 vaccine candidate clinical trials being available and used to assess future SARS-CoV-2 human challenge studies, should they be needed and should they be deemed safe and ethical to employ,” the NIAID said.

Arthur Caplan, a professor of bioethics at New York University Grossman School of Medicine and a leading ethics expert, noted approximately two weeks ago during a WCG Clinical webinar that the NIH was making preparations for challenge studies, and said “we could see an argument being made to do the challenge study.”

The University of Oxford is also putting together a weakened virus agent that researchers could potentially use in a challenge study if enrollment is insufficient using the standard trial model, Caplan said.

The ethics expert has argued that COVID-19 challenge trials can be designed to monitor participants closely, provide them with healthcare and enroll those significantly less at risk.

According to 1DaySooner, an advocacy organization for patients interested in enrolling in COVID-19 challenge trials, 33,491 patients in 151 countries have volunteered to participate so far.

“Yes, it’s dangerous, but I don’t think the risk is too high,” Caplan said. “And the consequences of not going faster is the world is exposed both to the damage of the virus and the economic consequences.” — James Miessler