Skip to main content

Tip Sheets

Reopening society pros outweigh risk from those vaccinated and unmasked

Media Contact

Gillian Smith

The CDC released updated guidance Thursday stating those who are fully vaccinated against COVID-19 no longer need to wear masks or physically distance, indoors or outdoors in most circumstances.


Luis Schang

Professor of Chemical Virology

Luis Schang is a molecular virologist who studies the interactions between viruses and cells, interactions which determine the outcomes of the infection and, consequently, pathogenicity. He says the benefits of returning to a more open society now outweigh the marginal risk of vaccinated people not wearing masks and distancing.

Schang says:

“The main purpose of face masks and social distancing during the COVID-19 pandemic has been to minimize the shedding and spread of the virus by infected but asymptomatic people. The highest risk of transmission has been in indoor settings with limited air exchange and large crowds, which may include a large number of individuals shedding virus and thus result in high virus concentration.

“Ample evidence indicates that vaccinated people contribute little to the spread the virus. With the continuous increases in the number of vaccinated people – reaching now about half of the eligible population, in addition to those who have been naturally infected – the proportion of people who may be asymptomatically infected and shedding virus continues to decrease. These decreasing numbers in turn result in lower potential for high virus concentrations, even in indoor settings.

“Although the risk of asymptomatic shedding and transmission is never zero, there is a need to also consider the benefits in the risk benefit analysis. The balance is continuously shifting more and more such that the marginal risk of not practicing universal mask usage and social distancing by vaccinated people, in particular in outdoor settings, becomes much smaller than the benefits of returning to a more open society.

“The minimal risk of not using masks or practicing social distancing by vaccinated people is thus now outweighed by the benefits of re-opening the society and economy. Personal responsibility is nonetheless still critical to ensure we finally fully control the pandemic as soon and effectively as possible so we can all soon enjoy a fully open society and economy. We should remain vigilant and ready to promptly change our behavior again if yet another effort was ever required.”

Cornell University has television, ISDN and dedicated Skype/Google+ Hangout studios available for media interviews.