Originally Posted by
doctoravios
I think we can say with certainty that none of the current vaccines provide sterilising immunity as this essentially means 100% (or at least close to 100%) prevention of infection. But the fact that they don't is not a problem - they are very effective at preventing serious illness and that will help enormously in turning the pandemic into manageable seasonal epidemics.
I was reminded of
Now That Grandma Has Been Vaccinated, May I Visit Her?
https://www.nytimes.com/2020/12/21/h...s-vaccine.html
which suggests that "ideally, the visitor would also be vaccinated as well.” The reasoning is not specified though.