Are COVID Reinfections As Common As They Seem?

The latest talk in the world of COVID is BA.5. In combination with BA.4 and BA.2.75 (which inexplicably someone gave the name “Centaurus”), these are the latest omicron subvariants. They share many features with omicron but have variations in their genetic code that render them distinct.

BA.5 has become the dominant variant in the U.S. (we think, based on fairly limited data). This fact implies that it must be either more transmissible than earlier variants or better able to evade existing immunity, or both. Without these features, it wouldn’t become dominant—a new dominant variant needs some advantage. Beyond the survival advantage, our (again, overall limited) evidence suggests that the variant is similar to the original Omicron (or BA.1, or BA.2) in terms of severity.

The presence of BA.5 has raised significant concerns—in some of the messages I get, I would say people are bordering on panic—about reinfection. Omicron in general, but perhaps the new variants even more so, show some immune evasion. We know already that COVID reinfection during the omicron wave was much more common than during the delta or alpha waves. This has translated, in popular discussion, to questions like “Are we all just going to get COVID every three weeks now?” and “I heard that vaccines and prior infection do not protect you at all anymore.”

You know how we can better answer these questions? Data.