SO DOES THIS MEAN THAT IMPERFECT MASKS STILL HELP BY REDUCING THE INITIAL VIRAL LOAD ON EXPOSURE? “Virus experts know that viral dose affects illness severity. In the lab, mice receiving a low dose of virus clear it and recover, while the same virus at a higher dose kills them. Dose sensitivity has been observed for every common acute viral infection that has been studied in lab animals, including coronaviruses. Humans also exhibit sensitivity to viral dose. Volunteers have allowed themselves to be exposed to low or high doses of relatively benign viruses causing colds or diarrhea. Those receiving the low doses have rarely developed visible signs of infection, while high doses have typically led to infections and more severe symptoms. . . . Low-dose infections can even engender immunity, protecting against high-dose exposures in the future.”

So even if everyone is ultimately going to be exposed, keeping the magnitude of the exposure down increases the likelihood that they’ll be asymptomatic, and later immune, without getting sick or dying. There’s your “herd immunity” strategy, of sorts.