Conventional wisdom says that if you're vaccinated and you get a breakthrough infection with the coronavirus, you can transmit that infection to someone else and make that person sick.
But new evidence suggests that even though that may happen on occasion, breakthrough infections might not represent the threat to others that scientists originally thought.
Ross Kedl, an immunologist at the University of Colorado School of Medicine, will point out to anyone who cares to listen that basic immunology suggests the virus of a vaccinated person who gets infected will be different from the virus of an infected unvaccinated person.
That's because vaccinated people have already made antibodies to the coronavirus. Even if those antibodies don't prevent infection, they still "should be coating that virus with antibody and therefore helping prevent excessive downstream transmission," Kedl says. And a virus coated with antibodies won't be as infectious as a virus not coated in antibodies.
Not enough evidence
In Provincetown, Mass., this summer, a lot of vaccinated people got infected with the coronavirus, leading many to assume that this was an example of vaccinated people with breakthrough infections giving their infection to other vaccinated people.
Kedl isn't convinced.
"In all these cases where you have these big breakthrough infections, there's always unvaccinated people in the room," he says.