apsmunro t1_ja4kgb7 wrote

It’s normal for all viruses to have a temporary impact on the immune system, but there is no evidence that in routine cases there is any lasting impact on the immune system.

There are cases where covid can trigger autoimmune conditions, and there appears to be some immune dysfunction in cases of long covid, but these are the exceptions.

I wrote a bit more about it here as there have been rumours circulating online about this topic.



apsmunro t1_j9swmf5 wrote

You can do randomised trials which are unblinded. Several have been done, including community studies in Denmark, Bangladesh and Burkina Faso. Mask adherence was very low in the intervention arms in the latter 2 of settings, which were done as cluster RCTs. In Denmark it was an individual level RCT so cannot assess masks as source control.

In short, inability to blind brings potential biases but is not a reason to not perform RCTs.