Masks, seatbelts, and why we wear them

CLINICAL MATTERS

DR. EDSEL SALVANA

One of the most frequent questions I get is whether it is finally safe to remove our masks. With the continued downtrend of Covid-19 cases in the country despite the emergence of new variants, does it make sense to continue wearing masks? Even with the Philippine government lifting the mask mandate, many Filipinos continue to wear their masks to maximize their protection. Is this a scientifically sound decision, and what are the alternatives to stay safe?

To say that masks have had a PR problem since the start of the pandemic is the understatement of the last three years. To kick off the confusion, the World Health Organization (WHO) advised against wearing masks at the start of the pandemic unless you had symptoms of Covid-19. This was based on the prevailing science at that time that, like SARS, Covid-19 was not contagious unless someone already had symptoms. In addition, while there was clear data that a surgical mask worn by a sick person decreased onward transmission, it was unclear whether a healthy person wearing a surgical mask decreased his or her risk of infection from a sick person. There was also the PPE shortage to deal with and so medical grade masks like N95 respirators were restricted to healthcare workers only. This then all blew up when it was definitively shown that Covid-19 could be transmitted by asymptomatic persons, at which point universal masking was advised using at least a cloth mask.

As more contagious variants like Delta and Omicron arrived, it became apparent that cloth masks were no longer adequate. The US CDC started recommending that the general public wear at least a surgical mask or a higher-grade medical mask up to an N95 respirator. High quality clinical studies have now shown that surgical masks do work to prevent Covid-19 infection when worn correctly and consistently. While N95 respirators seem to offer better protection in laboratory studies, clinical trials comparing these with surgical masks have not consistently shown a significant increase in protection against Covid-19. This is likely due to multiple factors, including proper fit-testing and the discomfort of wearing N95 respirators for extended periods of time. The mixed findings ignited extensive debate, with some people claiming that surgical masks were useless and only N95 respirators gave good protection. This was a counterproductive fight, which further confused people and led to some people prematurely removing their masks since they could not tolerate or afford N95 masks. To address these concerns, the US CDC modified its recommendations and stated that, in high-risk situations, you should wear a mask with the best fit, protection, and comfort for you.

Nothing says pandemic like wearing a mask. This is true mostly for Western societies. People in Asia, particularly in Japan, South Korea, and China, are habitual mask wearers and have no problems wearing them. Filipinos readily took to mask wearing, especially since we wanted to protect the most vulnerable people in our society. While the US and many Western countries relaxed their mask mandates as early as 2021, the Philippines partially lifted mandatory masking only in late 2022. Mask mandates in public transport and healthcare institutions remain in place. This has contributed to the continued low case rates even as mobility normalized and eventually exceeded prepandemic levels. In an unexpected reversal, the US CDC late last year began to recommend wearing masks indoors anew, especially in public transportation settings and when community levels of infection are high.

If there is one thing we learned during the pandemic, it is that no intervention is 100 percent effective. To minimize risk, especially the risk of severe disease, combining layers of protection is needed. Proven interventions that successfully decrease the risk of Covid-19 include vaccination, ventilation, face masks, eye protection (including face shields), and physical distancing. The more layers are used, the lower the risk. Even if there is breakthrough infection, this will tend to be mild since the amount of virus that gets through is substantially decreased.

At the start of the pandemic when there were no vaccines available, only the latter four options were available. This is why the Philippine government required eye protection in the form of face shields in combination with masks and physical distancing in order to mitigate the risk of widespread transmission and death. This worked quite well and flattened the Covid-19 curve in the early days of the pandemic. When Delta emerged, these interventions lost some efficacy due to the high viral loads of this variant. By then the vaccines had arrived, however, and were starting to make an impact. As we started to open up, more activities and venue capacity were allowed. This was initially done for outdoor settings since the ventilation was good. The rationale was that we wanted at least three layers of protection for a reasonably safe activity.

So for instance, if one was vaccinated, masked, and physical distance was maintained, then an activity was allowed. In restaurants where masks were removed to eat, only vaccinated individuals were allowed as long as there was physical distance and good ventilation. Face shields and eye protection were eventually removed as more and more people were vaccinated and due to the public clamor to do away with them. The Philippine Society for Microbiology and Infectious Diseases continues to recommend these for settings where community transmission is sustained, and for healthcare workers taking care of non-COVID patients in places with sustained community transmission of SARS-CoV-2 (https://www.psmid.org/face-shield-evidence-summary/). Continued face shield use would have significantly blunted the record numbers of transmission of Omicron in January 2022 and so it was really not a good time to remove them. Unfortunately, it was turned into a political issue and many people were needlessly infected and died as a result.

As Covid-19 case numbers continue to drop and vaccination and boosting rates increase, there is the perception that masks are no longer needed. Covid-19, however, is still circulating widely in the community and can still be deadly to vulnerable populations. The value of masking therefore remains, especially in those whom infection would be catastrophic. Just like we always wear seatbelts in cars for very rare accidents that may result in death, those at highest risk can choose to continue wearing masks when there is a lot of SARS CoV-2 that is circulating, especially in crowded settings. This doesn’t even take into account the protection masks provide against other respiratory diseases like RSV and the flu.

The question then should not be when we should stop wearing masks. The better question is, just like with seatbelts, why don’t we use something that can save our lives?

#seatbelts

Masking makes sense