An excellent article putting the focus on Ro, where it should be.



It is useful to note that Ro depends upon the product of the "number of interactions" between people and the "probability of virus transfer" if one of the people is infected (if either goes to zero Ro goes to zero). The distancing and shutting down the economy approaches to decrease the interactions which decrease Ro while doing massive economic damage does little about the probability of transfer.



We know from health care workers, with massive numbers of interactions with known infected people, can reduce the transfer probability by a huge fraction with the proper use of personal protective equipment (PPE). This includes a face mask to protect against transfer by large exhaled particles from talking, sneezing, and coughing, along with disposable outer garments and shoe covers. This effectively makes a bubble around individuals so the physical distance becomes irrelevant. We know that hospitals have internal Ro of much less than one (if they didn't they would be the source of infections).



If a significant fraction of the population used a civilian version of PPE the Ro for the society would be less than one and this will go away. By making local businesses, manufacturers, logistical systems have Ro less than one we can open businesses.



However, we don't have enough disposable PPE for this option so the civilian PPE must be re-usable. This virus can easily be inactivated by simple heating to greater than 140ºF (60ºC) for 30 minutes which is the temperature of a dryer, food warmer, dry air sauna, or an oven or toaster oven. If the temperature is less than 220ºF (100ºC), masks, gloves, outer garments, and shoes are not damaged and can be reused.



As we allow more contacts between people we have to decrease the transfer probability by using PPE. For more details:

https://www.dropbox.com/s/lvmhxl4nyybprsi/Protection%20in%20the%20Covid-19%20era%20V4.pdf?dl=0