![Face masks for covid-19, are face masks effective, do face masks stop covid-19, do face masks protect against coronavirus, face masks piracy, face masks coronavirus advice, WHO face masks advice, Hans-Georg Betz, coronavirus news, covid-19 news](https://www.fairobserver.com/wp-content/uploads/2020/04/face-mask-1.jpg)
Hans-Georg Betz, face masks shortage, are face masks effective against covid-19, are face masks effective against coronavirus, do face masks stop covid-19, face masks stop coronavirus, face masks advice covid-19, WHO face masks guidance, should we wear face masks in public, do I need to wear a face mask