This NPR item strikes me as being somewhat speculative (the fact that there are other explanations for apparent transmission by vaccinated individuals is not proof that the other explanations are correct). On the other hand, there does seem to be at least some evidence that the virus is different if it comes from a vaccinated person.
>>>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. . . .
"If you actually isolate virus from people who are getting a secondary infection after being vaccinated, that virus is less good at infecting cells," Pepper [an immunologist at the University of Washington] says. "It's not known why. Is it covered with an antibody? Maybe. Has it been hit by some other kind of immune mediators, cytokines, things like that? Maybe.
Nobody really knows. But the virus does seem to be less viable coming from a vaccinated person."
More studies are emerging that suggest there's something different about the virus coming from a vaccinated person, something that may help prevent transmission.
Whatever it is, the University of Colorado's Kedl says it's one more reason that getting vaccinated is a good idea.
"Because you're going to be even more protected yourself. And you're going to be better off protecting other people."<<<
Are vaccinated people who get COVID as likely to spread the infection as unvaccinated people? Scientists don't think so.
www.npr.org