As vaccine trials for COVID-19 take off gradually, so are the rising hopes of finding an ideal one. In the midst of this, there is an increasing support for a controversial trial known as 'human-challenge trial' that involves the infecting of healthy volunteers.

A grass-roots effort called 1Day Sooner has garnered over 1,500 volunteers from 44 countries, willing to participate in the much-debated scientific study. Not allied with any company or group funding or developing coronavirus vaccines, its co-founder Josh Morrison aims to convey that there is a great support for such trial.

"We want to recruit as many people as possible who want to do this, and pre-qualify them as likely to be able to participate in challenge trials should they occur," said Morrison, according to Nature.

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What is a human challenge trial?

In such a trial, healthy individuals volunteering for the study are intentionally exposed to the disease in order to understand its development, and then test treatments or vaccines on them. Such trials have been employed for studies involving other lethal infections such as cholera, dengue fever, influenza and malaria.

An advantage over standard methods

A standard vaccine trial is time-consuming and expansive as it involves thousands of individuals. That is because of its randomized nature that involves separate groups receiving the original vaccine or placebos. It also involves the examination of those who develop the disease during the course of their daily lives.

In theory, a challenge study could expedite vaccine development. It involves smaller numbers, and therefore, closer and quicker results. Morrison revealed that several volunteers were young people from urban areas who wished to contribute to the fight against the disease despite the risks. "Many note that they recognize the risk but believe the benefits of vaccine acceleration are so tremendous that it's worth it to them," he said.

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Increasing support for the trial

Perhaps, the trial's expeditious nature is the reason behind the increasing support for such studies aimed at vaccine development for COVID-19. Throwing their weight behind the idea, Nir Eyal at Rutgers University in New Brunswick, New Jersey, and his team, advocated that such a challenge trial can be conducted ethically and safely, in a recently published paper.

"We argue that such studies, by accelerating vaccine evaluation, could reduce the global burden of coronavirus-related mortality and morbidity," the researchers wrote.

Political support has also been lent for such a trial. Led by Democratic senators Donna Shalala and Bill Foster, 35 members from the US Congress, urged Alex Azar, director of Department of Health and Human Services to mull over human-challenge trials focused on vaccines for COVID-19.

Addressing ethical concerns

Morrison, who also serves as the executive director of Waitlist Zero, an organ-donation advocacy group, suggests that synchrony between volunteers and policy makers is important. "At the same time, we feel that the public policy decisions around challenge trials will be better informed if they highlight the voice of people interested in participating in such trial," said Morrison.

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Wellcome, a London-based research charity, is already discussing the logistics, and most importantly, ethics, behind a human-challenge trial for the development of a coronavirus vaccine. It's head of vaccines program, Charlie Weller, however, speculates if such a trial can actually speed up vaccine development.

What is paramount is that researchers need to decide on how volunteers can be safely exposed to the virus and determine if such a trial can be conducted ethically. "I think there's potential, but we've got so many questions to work through to understand whether it can help in the timelines we have," she said.