Harvard University director for its Healthy Buildings program Joseph Allen has sounded off on mixed messages about wearing face-coverings as the world goes into its second year of dealing with the pandemic. And the simple verdict is that we should all still wear face masks to protect ourselves from COVID-19.

Allen wrote in the Washington Post that everyone should wear face-coverings that offer 95% filtering protection such as medical-grade KN95 and N95 respirators or double-mask to boost protection levels. The article was released after the Biden administration reiterated how face masks are the country’s best defense against the coronavirus while efforts to procure the supply of vaccines are currently ongoing.

The Harvard associate professor also emphasized that face masks with a 95% level of protection or higher could be the key to reduce rising new cases that had suddenly spiked up with the emergence of new COVID-19 strains including the highly infectious South African, Brazilian, and UK variants of concern. Allen also shed light on the important aspects of filtration and fit, encouraging federal authorities to offer clear guidelines on which varieties of face coverings are acceptable and if American-made respirators and face masks are more preferable.   

According to Allen, several KN95 face masks that were made in China did not meet the National Institute for Occupational Safety and Health (NIOSH) standards, making American brands more highly recommended than those that are exported. The South Korean KF94 mask was also a top choice for the health expert.  
A more unpopular choice for the general public is double-masking with surgical masks that can offer up to 90% of protection though there are concerns that doing so can cause oxygen depletion and carbon dioxide retention. What Allen recommends for the general public is to get American-made N95 and KN95 respirators that allow for a more secure fit with head loops, before opting to wear Korean-made KF94s or double-masking.