Children & COVID – Part 3: Masks In Schools

Children & COVID – Part 1: Making sense of rates and vaccination and Part 2: Vaccine Update

COVID-19 blog series

The upcoming school year, which has already begun in many parts of the country, is already not the ones parents imagined it to be. The rapid rise of the Delta variant, a more contagious variant than prior ones, combined with lower-than-expected vaccination rates to create a fourth wave of COVID-19 infections across the nation. Parents who had been excited to send their children back to school in-person, in light of the myriad benefits for children both from a social-emotional standpoint and an academic one, are now finding themselves worrying about their children’s health and wondering how best to proceed with the 2021-2022 school year. Add to this the various bans on mask mandates around the U.S, and there is a confusing and worrisome situation.

Guidance from the Centers for Disease Control and Prevention (CDC) is clear: it recommends universal indoor masking in schools for all children ages two and up, as well as staff, teachers, and visitors, regardless of vaccination status. The American Academy of Pediatrics (AAP) is similarly clear in its recommendation that all children two and over engage in universal masking indoors at school.

Let’s look at the data underlying these recommendations. It is well documented that masks work in two ways: by blocking the exhalation of respiratory droplets that can contain virus, as well as by filtering the air inhaled by an individual wearing a mask, ensuring that larger virus-containing droplets cannot pass through the mask.

Since the start of the COVID pandemic, there have also been a number of studies evaluating the effectiveness of masks in preventing COVID-19 transmission and infection. These studies are purely observational at this point, meaning they are not the “gold standard” of a randomized control trial (RCT) that evaluators aim for, but for many reasons an RCT would be impractical. The bottom line is that from what we know now, masks work in preventing COVID-19 transmission.

One such study was of a hair salon in Missouri in which two stylists who had active COVID-19 infections and were symptomatic, interacted with 139 patrons. Per local ordinances, there was a mask mandate in effect, so all stylists and patrons were masked. Of the 67 patrons evaluators were able to reach, none experienced a COVID infection.[1]

Even more powerful are community-level studies that analyze rates of COVID-19 infection in relation to mask mandates. Researchers in Kansas looked at data from summer 2020 and found that counties with mask mandates saw case rates decrease by 0.08 per 100,000; whereas, counties without mask mandates saw cases increase by 0.11 per 100,000.[2] Another study looked at rates across the U.S. between March and October 2020, and found that areas with mask mandates saw a decrease in weekly hospitalization rates of up to 5.6 percentage points for adults, as compared to growth in rates in the four weeks leading up to the implementation of a mask mandate.[3]

Coming back to the situation in schools today, we see a patchwork system of often contradictory positions on mask mandates. As of the writing of this blog, eight states had bans on mask mandates in place, while 14 states and the District of Columbia had state-level requirements that masks be worn in schools. This situation is ever-evolving, as there are lawsuits challenging stances on mask mandates, and many local jurisdictions are closely watching infection rates and adjusting as necessary.

It is too early in this school year for there to be any comprehensive data to analyze on in-school transmission, but some early anecdotal evidence indicates that in-school transmission is higher, likely owing to the more contagious nature of the Delta variant. Data from the Los Angeles Unified School District showed a rate of eight cases of COVID-19 per 1,000 students for the period of early August 2021, which, albeit low, is quite an increase from rates in early June 2021, when there was approximately one case per 1,000 students.

As a final consideration, is it important to note parental preference. A Kaiser Family Foundation survey conducted nationwide between July 15-August 2 found that 63 percent of parents of children age 5-17 were in favor of schools requiring masks be worn by unvaccinated students and staff.

Some have voiced concerns that mask-wearing will impede children’s development, particularly in the area of speech acquisition and understanding how to read emotions on faces. It is for this reason that the American Academy of Pediatrics (AAP) has not recommended mask wearing in children under two. However, a study of older children found that they could still generally read emotions of adults even while the adult was masked. In 2012, researchers found that children ages 3-8 were still able to correctly classify expressions of masked individuals. Researchers further point out that it is important to ensure lots of face-to-face unmasked communication at home to help children move along in their linguistic and social-emotional development.

It is clear that masks work, and that they are a particularly easy and effective way of preventing illness from COVID in unvaccinated populations. Given that children under 12 are not yet eligible to receive a COVID-19 vaccine, there is a strong argument for requiring masks in schools with young populations. Here in South Carolina, the headquarters of ICS, the South Carolina Chapter of the American Academy of Pediatrics has come out in clear support of universal masking in South Carolina schools.


1 Hendrix MJ, Walde C, Findley K, Trotman R. Absence of Apparent Transmission of SARS-CoV-2 from Two Stylists After Exposure at a Hair Salon with a Universal Face Covering Policy – Springfield, Missouri, May 2020. MMWR Morb Mortal Wkly Rep. Jul 17 2020;69(28):930-932. doi:10.15585/mmwr.mm6928e2

2 Van Dyke ME, Rogers TM, Pevzner E, et al. Trends in County-Level COVID-19 Incidence in Counties With and Without a Mask Mandate – Kansas, June 1-August 23, 2020. MMWR Morb Mortal Wkly Rep. Nov 27 2020;69(47):1777-1781. doi:10.15585/mmwr.mm6947e2

3 Joo H, Miller GF, Sunshine G, et al. Decline in COVID-19 Hospitalization Growth Rates Associated with Statewide Mask Mandates — 10 States, March–October 2020. MMWR. February 12, 2021 / 70(6);212–216


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