Phoebe Garrett has attended university lectures without catching COVID-19; she even hosted a party where everyone subsequently tested positive except her. “I think I’ve knowingly been exposed about four times,” the 22-year-old said.
In March 2021, she participated in the world’s first COVID-19 challenge trial, which involved dripping live virus into her nose and pegging her nostrils shut for several hours, in a deliberate effort to infect her. Still her body resisted.
Most people know someone who has stubbornly resisted catching COVID-19, despite everyone around them falling sick. Precisely how they do this remains a mystery, but scientists are beginning to find some clues.
Garrett is not the only challenge trial participant to have avoided becoming infected. Of the 34 who were exposed to the virus, 16 failed to develop an infection (defined as two consecutive positive PCR tests)—although around half of them transiently tested positive for low levels of the virus, often several days after exposure.