In February 2021, scientists at Imperial College London gained approval to conduct an [human challenge trial, or] HCT of COVID-19 in a small group of young, healthy volunteers.
Like for much of the work in the Common Cold Unit, the goal of the study was to better characterize the trajectory of COVID and its associated immune response.
In late March, the scientists reported their first results, in the journal Nature Medicine. They found, among other discoveries, that subjects tended to first test positive by PCR fewer than two days after exposure—much more quickly than many had thought.
But principle is far from reality. While some experts emphatically support COVID HCTs and have advocated for them since March 2020, others doubt that the risks currently outweigh the benefits. “I’m still skeptical of whether this study was sufficiently justified,” says Seema Shah, a bioethicist at Lurie Children’s Hospital of Chicago.
Intentionally infecting people with the virus that has disrupted life across the planet for the past two years and killed more than 6 million people worldwide might seem difficult, even impossible, to justify. But newly developed treatments mean that such studies are now more feasible than they have ever been, and, as the pandemic continues to trudge on, they could answer essential questions that might otherwise prove insoluble.
