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