Mask Guidance Should Be Clarified
As a group of scientists, public health officials, epidemiologists, health care workers, educators, community advocates and concerned citizens, we are asking the Centers for Disease Control and Prevention to clarify their recent guidance to recommend that masks should continue to be used indoors until cases of infection in the United States drop to much lower levels, and until a sufficient majority of American adults and children have had the opportunity to be vaccinated. We urge further communication to help individuals, businesses, schools and places of worship make safe decisions. We also urge CDC to issue clear guidance for transparent vaccine verification, because given the current climate of politicization of masks and vaccines, the honor system mechanism will place Americans’ health at risk.
While the significance of the speed with which vaccines against SARS-CoV-2 are being developed, approved, and distributed is an accomplishment which cannot be overstated, vaccines are only one of many critical tools against COVID-19. CDC’s easing of the indoor masking and distancing mandate for vaccinated people at this time is dangerously premature.
The risk of transmission outdoors is extremely low except in crowded circumstances, so it’s reasonably safe for both vaccinated and unvaccinated people to be outdoors without wearing a mask. But the messaging lacks critical nuance – it should define how close is too close, what constitutes crowding, advise avoidance of being downwind of people who are exercising or vocalizing forcefully. The public should also be advised to always have a mask with them, in the event that they unexpectedly find themselves in a crowded situation or need to go indoors.
But there are still too many unknowns to justify revoking indoor public masking and distancing mandates for vaccinated people at this time.
Although CDC claims to have strong data supporting this change in guidance, on review of the data cited in their Science Brief, it does not fully address these questions:
- How long mRNA vaccine-acquired immunity will last.
- How well the mRNA vaccines will perform against emerging variants of concern.
- Whether mRNA-vaccinated, infected individuals will be susceptible to long COVID.
- How likely it is that mRNA-vaccinated, infected individuals will develop viral loads sufficient for disease transmission.
- How the Johnson & Johnson viral vector vaccine will perform in these regards.
As of April 26, CDC reported 9245 (known) breakthrough infections, statistically rare but affecting a significant number of people. The rate of such infections depends on the precautions people take.
While we continue to make progress with the vaccine rollout, we are not yet where we need to be. And until these questions are answered, given the ongoing cases, deaths, and disabilities, as well as the need for clearer guidance and a reliable vaccine verification system, all people need to continue to wear their masks indoors.