I suspect people have a question in their minds for months ("Will the upcoming vaccines prevent a vaccinated person from carrying and spreading the virus?"), an

I suspect people have a question in their minds for months ("Will the upcoming vaccines prevent a vaccinated person from carrying and spreading the virus?"), and whatever is the first credible reply to that question, they cement it in their understanding ("you may still spread covid if you're vaccinated"). Now we have far more real world data and it appears that even if a vaccinated person is carrying an asymptomatic infection that they shed very little virus. This is not a certainty, but things are leaning that way. But people can't replace the old "fact" they knew with the new "fact".