So long as the anti-fogging air exchange is done through a less than virus sized filter, all good.
If it uses circulated unfiltered air to carry away moisture then it might not be worth having.
That may be a bit steep of an assessment, but unless it's sealed properly it's not 100%.
Is anything 100%? Of course not. you could have virus particles in your hair, take off your NBC-95 o whatever, and inhale virus right then after hours of faultless protection.