I was reading something similar.
If you are in an environment where there are lots of virus in the air the mask will not protect you. You need a full blown chem warfare mask or CDC type mask.
My mask is a particulate respirator with a seal. Which is a little better then a plain mast.
Also N95 only filters down to 0.3 microns, Coronavirus is 0.12.
Now wearing a mask does keep you from rubbing your mouth directly with your hands, that helps.
The mask can also decrease the chance of catching other infections that could be confuse for Cornavirus.
If I know the virus is near, I will wear my mask and pray for the best.
Don’t forget to wear goggles. Your eyes are also a point of entry.