It’s not helpful to talk about herd immunity with COVID-19

crowd wearing PPE

In the face of the frightening uncertainty swirling around COVID-19, it’s natural to clutch at simple suggestions about how to halt its progress and reduce its impact.

Because herd immunity has worked previously, we invoke it now. But COVID-19’s viral characteristics make this unlikely to be helpful.

The most basic problem is the difficulty of being certain about the nature and duration of SARS-CoV-2 immunity.

Recent studies have shown that antibodies tend to wane after this infection and reinfection has been documented; we do not know what immunity is conferred.