Federal health officials have begun preliminary work to establish protocols for a “challenge” trial of a COVID-19 vaccine, including creating a strain of the virus that could be used. Reuters reported it on Friday.
A ‘challenge test’ is a controversial idea to deliberately infect a few hundred young, healthy volunteers with the novel coronavirus in a controlled environment to test for a possible vaccine.
Several clinical trials of several vaccines are already underway, and a challenging trial is unlikely to replace them, the National Institute of Allergy and Infectious Diseases (NIAID) told Reuters.
But The Hill has previously reported that the idea has been gain some ground among certain advocacy groups and legislators.
NIAID has reportedly begun its initial planning. The agency prioritizes large-scale field tests to evaluate COVID-19 vaccine candidates, but is open to the possibility of challenge tests for future generations of vaccines or treatments.
The Hill has reached out to NIAID for comment.
A challenge test would deliberately infect a few hundred young, healthy volunteers who had first received the potential vaccine as a placebo. Those who are selected are well informed about the risks.
This would allow the effectiveness of a vaccine to be determined more quickly than a traditional clinical trial, which would require researchers to wait for some of the participants over the course of their daily lives.
Challenge studies have been conducted in the past, but they are usually done to test vaccines for diseases that can be cured, such as malaria. It would be a sharp break in advance to do a challenge test for a virus with no known cure that is as deadly as the coronavirus. Even if the volunteers were all young and healthy, this would not completely reduce the risk of serious illness.
In addition, they are also conducted among much smaller groups, raising questions about how such trials would be useful at this stage of the pandemic, when the virus is so widespread.
Some of the top vaccine candidates are already working under an accelerated time frame, and have started Phase 3 trials testing safety and effectiveness in tens of thousands of people.
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