Human challenge trial: The ethics of infecting volunteers with Covid-19 - Vox

"A conventional trial vaccinates people and then waits months to see if they get infected anyway while they go about their normal lives. A challenge trial eliminates the whole wait-and-see period by vaccinating people, exposing them to the virus on the spot, and seeing how well the vaccine protects them. Results come in extremely fast, and they’re reliably instructive because scientists can control all the conditions. They know exactly who was exposed, how big a dose of virus they were exposed to, and how their immune system responded day by day.

A human challenge trial is set to begin in London in January, assuming it gets final ethics and regulatory approval. Scientists have run such trials in the past for influenza, malaria, typhoid, dengue, and cholera, but this will be the first for Covid-19....

Only healthy volunteers aged 18 to 30 will be allowed to participate. The challenge trial is not meant to replace conventional clinical trials — the different types of trials will proceed along parallel tracks....

Many young people are clamoring to participate in a challenge trial. The advocacy group 1DaySooner has gathered the names of nearly 39,000 people in 166 countries who say they’d be interested in volunteering.

In July, the group sent an open letter to Francis Collins, the head of the National Institutes of Health (NIH), calling for human challenge trials in the US. The letter was signed by more than 30 Nobel laureates and many prominent philosophers and psychologists, including Peter Singer, Steven Pinker, and Rebecca Goldstein. They wrote: “If challenge trials can safely and effectively speed the vaccine development process, there is a formidable presumption in favor of their use, which would require a very compelling ethical justification to overcome.” ...

“I’m not convinced that we can actually obtain informed consent from people given that we’re still seeing the emerging effects of long Covid,” said Angela Rasmussen, a virologist at Columbia University. She was referring to the fact that, for at least 10 percent of people who contract Covid-19, some of the disease’s poorly understood effects — ranging from brain fog to lung scarring to heart conditions — can last for months. Scientists don’t yet have a clear understanding of the risk factors for long-term Covid-19, nor can they predict its duration.

Some argue this isn’t a problem: The researchers running a human challenge trial can just inform the volunteers that a lot of uncertainty remains about Covid-19, and that they might be signing up for long-term disability. The volunteers can consent to the uncertainty....

There’s another complicating factor here: money. If volunteers are offered payment for participating, there might be a problematic incentive for low-income people to take part in a trial that could harm their health, which is arguably exploitative...."