A Conversation on the Bioethics of Human Challenge Trials

Earlier this year, the United Kingdom announced it was going to be funding a government-sponsored trial where they were looking for volunteers to be purposely exposed to SARS-CoV-2.

When hearing this, one of the first things that comes to mind is the Tuskegee Syphilis Study. This was the infamous US-funded study done in Alabama that wanted to witness the progression of syphilis. Whereas, this new Human Challenge experiment is studying the progression of COVID-19, they are not withholding treatment from the volunteers. While it is not a true apples-to-apples comparison, the idea of the government running an experiment where people are signing up to become infected with COVID-19 does raise ethical questions, especially as vaccines and therapies for the virus are available.

The COVID-19 Human Challenge is a UK-government-funded study planning to expose 90 young adults to SARS-CoV-2. The investigators’ goals are to understand the effects of the virus, potential progression of COVID-19, and the immune system’s response to it.

“We are asking for volunteers aged between 18 and 30 to join this research endeavor and help us to understand how the virus infects people and how it passes so successfully between us,” trial investigator Chris Chiu, PhD, of the Department of Infectious Disease at Imperial College London said. “Our eventual aim is to establish which vaccines and treatments work best in beating this disease, but we need volunteers to support us in this work.”

Human challenge trials have been conducted in the past studying a variety of diseases and viruses including malaria, influenza, typhoid, cholera, and norovirus. Whereas, typical human challenge trials are attempting to find new therapies or vaccines, this trial is a departure in that there are therapies and vaccines available as well as an unpredictability to the virus and how it will affect individuals being that COVID-19 is still relatively new.

“We are now in this interesting point of the pandemic where we have several vaccines that have been authorized and I think the big question on a lot of peoples’ minds is why do a challenge now?” Seema Shah, JD, associate professor in Pediatrics at Northwestern University Medical School and an associate director of the Bioethics Program at Lurie Children’s Hospital, said. “I don’t think that this question has been answered as well by the researchers and the justification for doing this trial right now.”

Whereas, the Tuskegee Syphilis Study created a deep mistrust of public health and vaccines that lingers today in the Black community, as well as living in an age of misinformation leading to vaccine hesitancy, Shah says public trust is paramount when conducting these human challenge trials.

“It is really critical to be thinking about trust because research is one of those things that we are asking some people to take on risks for the benefit of others in society,” Shah said. “Whenever you do that, especially in light of the long history of vulnerable groups being exploited in research, people now realize that it’s absolutely critical to have good reasons for asking people to take on these risks and when people take on risks that they are protected and they are respected.”

Shah was a member of a commission looking at a potential human challenge trial for the Zika virus a few years ago. “That was one of the more difficult things I had to do in my career where we really did have to come up with a recommendation of should these trials go forward or not,” Shah explained. “I’m relieved that is not my role in this pandemic.”

Shah said the commission decided to not recommend to the National Institutes of Health to move forward with the Zika trial. At that time, she said there were too many unknown variables that could affect people outside the trial including potential infection—as the virus can be transmitted sexually between partners.

Contagion spoke to Shah about the potential differences between this COVID-19 human challenge compared to previous ones, the process of signing up for such studies, and trying to decipher if a human challenge trial is worth the risk.