1 simple way to understand how effective the Covid-19 vaccines are

All of the approved Covid-19 vaccines — all of them — are more effective at preventing Covid-19 than the average seasonal flu shot is at preventing the flu. But you wouldn’t know it from how they’ve been talked about in some reports about the vaccines.

As my colleague Kelsey Piper wrote recently, the most important statistic about the vaccines approved for emergency use in the US — Pfizer/BioNTech, Moderna, and Johnson & Johnson — is zero: zero deaths or hospitalizations among the patients who were given the vaccines in their...