In light of the recent Federal Judge action that overturned the TSA’s mask mandate, we strongly support the Department of Justice’s appeal to keep a mask mandate on public transportation in place.

We call on the CDC and TSA to maintain a mask mandate for public transportation (train, bus, air travel, and other forms of public transit) due to the continued spread of COVID-19, the increasing number of cases in several states (NY, OR, FL, for example) and the long term consequences of infection. Public transportation, including bus, train and air travel, amplifies the national and international spread of COVID-19 and promotes the development of new variants.

The Omicron sub-variant (BA.2) has caused a considerable increase in positive cases across Europe (as indicated by excess mortality data), the US, and Asia, with China imposing strict lockdowns in an effort to curb the transmission of the virus. Continued transmission has already given rise to emerging sub-variants, BA.4 and BA.5, and others, which are rapidly rising in Denmark, Germany, Belgium, the UK, and parts of Africa. The known consequences of infection, causing harm to long-term health and disability even for healthy individuals (Long COVID), and the high rates of growth of these new variants imply they pose great risk to communities, and are especially life threatening to those vulnerable to severe disease. This risk to human health is exacerbated with repeated infections, with evidence from the CDC that reinfections are pervasive and may occur shortly one after another.

The high infectiousness of current variants is evident from the inability of airlines to maintain regular operations when mask regulations are removed. Recent reports demonstrate that a massive increase in SARS-CoV-2 transmission among airline personnel has led to numerous cancellations. This highlights the necessity to extend mandates for mitigation measures that limit transmission of COVID-19 on flights. Removing mask mandates when case numbers are high would eliminate one more barrier to transmission, would place the health of passengers, personnel, and their families at risk, could worsen the economic impact on airline businesses, and would further undermine trust in public health authorities.

Current and emerging variants’ extreme contagiousness requires managing air quality in all ways possible. This should remain the highest of priorities in closed, shared-air environments. Ventilation and filtration of the air in public transportation including buses, trains, as well as airports and on airplanes is variable. For example, ventilation during airplane boarding and disembarking is well known to be poor, and airport ventilation is generally limited. This creates an environment in which all passengers and staff are forced to breathe each other’s exhaled air, in the same way that secondhand cigarette smoke was doing before the regulation to restrict it. This lack of transmission risk mitigation is especially endangering the immunocompromised and those too young to vaccinate or mask.

In view of TSA’s statement—that guidelines about masking for public transportation will be informed by community levels, risk of new variants, national data, and the latest science—we submit that the manifest risks described in this document are imperative to such considerations. Therefore, we request that the TSA maintain mask mandates on public transportation.