Why Scientists Want to Infect People With Covid-19

The concept of a human challenge trial for Covid-19 is gaining momentum. A challenge trial means healthy volunteers would be purposefully infected with Covid-19 in order to test a vaccine. The idea is that this would speed up the normal vaccine testing process. Traditional phase 3 clinical trials sign up thousands of participants, inject some with a vaccine and others with a placebo, and then wait for people to encounter the virus in everyday life. In a challenge trial there’s no waiting on people to catch a virus. But a challenge trial for Covid-19 could be especially…