If the mask were all N95 rated then the mask might help. A piece of material across your mouth and nose does very little. Your eyes are not covered and are susceptible to the virus too. You need a mask which covers the whole face with a filtered air supply blowing air into the mask.
Its been stated time and time again... The mask isnt to protect you, its to protect others from you....
More 24/7 numb nuts on this thread...