Warren CornwallScience’s COVID-19 reporting is supported by the Pulitzer Center and the Heising-Simons Foundation.In the early days of the COVID-19 pandemic, tens of thousands of young volunteers offered to risk their health by letting scientists intentionally infect them with the pandemic coronavirus, hoping to speed the hunt for a vaccine or treatment.
Several research groups announced plans to run these so-called human challenge trials, even as some scientists questioned whether they could be conducted ethically.Now, with the recent news that conventional human trials have produced at least two very promising vaccines, scientists are debating whether planned challenge trials are still needed.