Already have Save Life With Care? SIGN IN or REGISTER

“Human challenge trials,” where healthy volunteers would be exposed to Covid-19, explained

Advocates say human trials could speed up the development of a coronavirus vaccine.

As a journalist who covers philanthropy, one of the most frequent questions I get about the coronavirus crisis is how ordinary people can help.

A couple things leap to mind. GiveDirectly is giving money to poor Americans struggling with unemployment and other hardships; you can also donate money to other public health charities helping poor countries handle a sudden surge in demand for doctors and hospitals.

Now, a bioethicist and two epidemiologists are proposing a bolder option: You can volunteer to get infected yourself.

In a recent article published in the Journal of Infectious Diseases, bioethicist Nir Eyal and epidemiologists Marc Lipsitch and Peter G. Smith called for “human challenge studies” to test the effectiveness of coronavirus vaccines as they’re developed. These studies would involve testing the vaccines on a group of volunteers who have been knowingly exposed to the novel coronavirus that causes Covid-19. The hope is that it will allow researchers to ascertain more quickly and conclusively the effectiveness of the proposed vaccine.

Human challenge studies are commonly conducted with less lethal diseases like malaria or schistosomiasis. My colleague Kelsey Piper interviewed John Beshir, a volunteer in a malaria vaccine trial, last year; Beshir is an active donor to anti-malaria charities and saw his volunteering as an extension of his monetary support for the cause.

But malaria, if properly treated, has a low death rate for young and healthy people (that it still kills hundreds of thousands of people every year is partially a reflection of the poor availability of treatment in heavily affected African countries). Covid-19 is different. About 0.66 percent of people who are infected die from the disease. And while a recent study showed that death rates are much lower for younger people (0.03 percent for people in their 20s) the data on which it’s based is from the early stages of the Chinese outbreak in February. There’s still a lot we don’t know about the disease and its lethality.

Activist Josh Morrison, whom I know from his day job advocating for living kidney donors (like me), has started a website soliciting volunteers willing to take on that deadly risk for the sake of speeding up vaccine development. As of this writing, about 450 people have expressed provisional interest in volunteering (including me, though I may not be eligible with only one kidney).

Signing up doesn’t commit you to anything, and the website isn’t recruiting for any current trial. No vaccine is in the stage of development where a human challenge trial would make sense. The Milken Institute counts 51 different vaccines currently in development, with only a small handful in Phase I trials, which involve making sure the vaccine isn’t dangerous to humans. After that comes Phase II trials, which use a larger sample and do preliminary tests for efficacy and to find an optimal dose with the best balance of side effects and effectiveness. Some studies combine Phases I and II, which could speed the process up.

Eyal, Lipsitch, and Smith propose using a human challenge trial to replace Phase III, where larger-sample effectiveness tests take place (and which are, at the very least, months in the future). Instead of a typical Phase III, a human challenge trial could involve fewer people and run for a much shorter period of time, since researchers would not have to wait for volunteers to be exposed to the virus. A real human challenge trial would involve intensive health screening for volunteers, as well as voluminous risk disclosures to ensure that volunteers know exactly what they (we) are getting into.

But the push to sign up volunteers is forcing a broader conversation about whether this kind of trial is necessary or ethical, given the death toll that coronavirus threatens to leave in its wake. The ethical question here is knotty, and depends on both empirical questions — Would a human challenge trial actually speed up vaccine development? How many lives would be saved by speeding up development by, say, one month? — and values questions.

The big one: Is it acceptable to ask volunteers to risk their lives to speed up vaccine development? And if so, should they be eligible for nominal compensation (like lost wages) or something more?

How human challenge trials work

Testing something like a coronavirus vaccine normally happens by gathering a group of healthy people, giving half of them the experimental vaccine and the other half a placebo, and waiting for them to get infected with the relevant disease in the course of their regular lives. Then you compare the groups.

The problem with the coronavirus is that if you’re a healthy person who’s practicing social distancing, you probably aren’t going to get infected. That makes it hard to do a real comparison between the vaccinated and unvaccinated groups. Maybe they both end up the same because no one in either group was exposed to the pathogen. If that’s the case, the trial hasn’t told us anything useful.

How can we help?

Send as a message

Please leave your message and contact details in the form below