[cas14655]

People keep saying this so there is probably something to it. I mean, not even the most optimistic mask studies show a long-term complete protection from all pathogens that can cause colds but okay, let's take it at face value: your wife is protected from colds because she wears N95s.

What this means is that your wife's immune system isn't getting challenged and isn't learning about the ever changing pathogens around it. It's not building immunity to the various strains every winter and it therefore can't get any cross-immunity ie against SARS-COV-2 [1].

All we know about the immune system suggests this is not good in the long term.

If true and I kind of hope it's not for this reason, your wife might be setting herself up for a very serious disease down the line. I hope this is not the case and wish both of you the best of luck.

[1] https://www.mpg.de/17434954/0907-moge-prior-exposure-to-comm...