Do vaccinated people still need a mask outdoors?

CHICAGO --- Should you wear a mask outside if you are fully vaccinated? The answer is yes, but not because of the risk of infecting a passerby with COVID-19.

Northwestern Medicine experts unpack this confusing public health and societal question.

“The likelihood of a fully vaccinated person transmitting SARS-CoV-2 while outdoors is exceedingly low,” said Dr. Benjamin Singer, assistant professor of medicine in pulmonary and critical care at Northwestern University Feinberg School of Medicine. “Accordingly, the incremental reduction in transmission risk from wearing a mask is minuscule for vaccinated people.”

The vast majority of people need to become vaccinated

Northwestern experts say upholding the social norm of mask-wearing outdoors and indoors until the vast majority of people have become vaccinated over the next few months is important. It’s also a symbol of solidarity and contributes to a culture of mask wearing.

“We have seen this in Israel where they have rescinded the order to wear masks outdoors, but this is consistent with their successful mass vaccination strategy where 80% of citizens 16 and older have been vaccinated,” said Dr. Sadiya Khan, assistant professor of medicine in epidemiology. “Masks are still required indoors in Israel, where there is the majority of risk for transmission.

Social courtesy and protecting children are reasons to mask up 

“Social courtesy is the reason, in my opinion, to mask up when outside,” said Mercedes Carnethon, vice chair of research in preventive medicine at Northwestern. “I also feel strongly that until we have vaccines for children, we need to continue to model the behavior of mask-wearing for them. 

“In settings where the adults are vaccinated, they are at low risk, however, children don’t know that. They behave in ways that they see respected adults behave. As more adults become vaccinated, we risk seeing the disease continue to spread among children.”