I was recently stunned to learn of the serious consideration being given to deliberately infecting human volunteers with the SARS-CoV-2 virus in order to assess the effectiveness of potential COVID-19 vaccines.

My first reaction was that the advocates of such “human challenge studies” had gone so mad with panic that they had forgotten the history and horrors of medical experimentation on humans. But on closer inspection, I saw that they included some of the world’s most respected vaccine researchers and medical ethicists, and even the World Health Organization.

As far as I can tell, their principal argument is that waiting for an answer from naturally occurring infections will take too long. The new coronavirus has already infected 6.5 million people worldwide and killed more than 386,000, including 107,000 in the United States alone. And in the absence of safe, effective vaccines and treatments, measures aimed at controlling the virus’s spread are ruining economies around the world. The WHO’s recent white paper on the use of human subjects for vaccine research makes it clear that such trials are a desperate last resort.