Question: Leaders across the spectrum have finally gotten on board with recommending the wearing of masks, but I fear that people think that as long as they wear a mask they can do whatever they want. Isn’t social distancing, especially indoors, more important than wearing masks to curtail the spread?

Answer: Social distancing and mask wearing are both extremely important for curbing virus spread. We should be doing both when we are out in the world in the presence of others. Social distancing does not negate the need for masks and masks do not negate the need for social distancing! While neither of these interventions make the risk of infection nil, if we want to keep ourselves and each other safe, we should be practicing both. We should also be helping to ensure that health providers have necessary personal protective equipment. Read on for the data…

A meta-analysis, “Physical distancing, face masks, and eye protection to prevent person-to-person transmission of SARS-CoV-2 and COVID-19”, published in Lancet earlier this month found that proximity increased risk of infection (absolute risk 12·8% with shorter distance vs 2·6% with further distance, risk difference −10·2%, 95% CI −11·5 to −7·5). Additionally, the strength of association was larger with increasing distance and remained regardless of face mask type worn. Study authors found an even higher risk reduction related to the use of face masks (absolute risk of infection 17·4% with no face mask vs. 3·1% with face mask, risk difference −14·3%, 95% CI −15·9 to −10·7) though most of the face mask studies were among health workers in hospital settings. Generally in non-healthcare settings, it is unclear to what degree face masks protect the wearer. What is clear in non-healthcare settings is that face masks keep the wearer’s germs from more widely spreading, thereby reducing the risk of infection for others (for more, see Q&A of 6/22).

Finally, the fear your raise reminds me of earlier conversations about condoms and HIV — there was a time when people were concerned that in teaching people about the relationship between condoms and reduced HIV acquisition risk and in widely distributing condoms, we would be encouraging more risk sexual behavior. Evidence shows that such programs do not increase risky sexual behavior and can even promote delayed sexual initiation among youth (among other positive findings). When it comes to COVID, I think the more comprehensive risk reduction communication we see, the more risk reduction behaviors we’ll see.