The CDC and WHO have posted studies.And I may add...what factual data do you have that proves that masks are effective at preventing the transmission of viruses? Just because someone you work for told you so does not cut it. Show us some facts that have not been grabbled by the liars that are making this virus out to be the false crisis they want it to seem to be. Did you have to wear a mask at work in the years past during flu season? If your answer is no then that proves it right there. I know the answer because I have spoken to many nurses, doctors and two of my close friends that are both ER doctors. Masks are just now something we just absolutely have to wear to stop the transmission of a virus? It makes no sense.