Masking in Schools: What Is the Evidence?

IDSE | By Kate O’Rourke | January 4, 2022

State school systems have taken different approaches to the CDC’s recommendations for universal indoor masking by all students (ages 2 years and older), staff, teachers and visitors to K-12 schools, regardless of COVID-19 vaccination status.

According to Burbio, a data monitoring service, states such as California, Illinois and New York have mandated masks in schools; states such as Oklahoma and Utah have banned masks in schools; states such as Arizona, Florida, Texas and Utah have banned mask mandates in schools and then had these bans overturned; states such as Nevada have mandated masks for schools in counties with more than 100,000 people or with a schoolwide COVID-19 outbreak; and other states, such as Colorado, Georgia and Maine have issued no policy, leaving it to local regulators to decide.

So, what do we know about masks in schools?

According to Jade Fulce, a spokesperson for the CDC, as COVID-19 cases began increasing nationally in mid-June 2021, driven by the delta variant, protection against exposure remained essential in school settings. She said the CDC recommends universal indoor masking in the school setting because of the highly transmissible nature of the delta variant, the mixing of vaccinated and unvaccinated people in schools, the fact that not all children are eligible for vaccination, and the low levels of vaccination among youth who are eligible. As of Dec. 12, 1.3% of children 5 to 11 years and 6.5% of children 12 to 17 are fully vaccinated against COVID-19.

Vaccination rates among educators appear to be higher. The National Education Association, the nation’s largest union representing nearly 3 million educators, said 90% of members have received at least one COVID-19 vaccine as of Sept. 9.

“I strongly agree with the CDC guidance that recommends masking in schools because masks have been shown to decrease COVID-19 transmission in the school setting across several studies. This should be part of [a] multipronged, layered approach to protect children and school staff from COVID-19 infection, including vaccination, physical distancing, ventilation, testing, cleaning and disinfection,” said Ishminder Kaur, MD, an assistant professor of pediatrics in the Division of Infectious Diseases at the David Geffen School of Medicine and the medical director of the Pediatric Antimicrobial Stewardship Program at UCLA Mattel Children’s Hospital, in Los Angeles.

In September, the CDC released three studies in its Morbidity and Mortality Weekly Report that highlighted the importance of using layered prevention strategies, including universal masking to stop the spread and minimize disruptions to school operations for safe in-person education. These studies found that school districts without a universal masking policy in place were more likely to have COVID-19 outbreaks.

Nationally, counties without masking requirements saw the number of pediatric COVID-19 cases increase nearly twice as quickly during this same period. One report from Arizona revealed that schools in two of the state’s most populous counties were 3.5 times more likely to have COVID-19 outbreaks if they did not have a mask requirement at the start of school compared with schools that required universal masking on the first day. Another report that looked at national data found that during the two weeks following the start of school, the average change in pediatric COVID-19 case rates was lower among counties with school mask requirements (16.32/100,000 per day) compared with counties lacking school mask requirements (34.85/100,000 per day). A third report studied COVID-19–related school closures and found that despite an estimated 1,801 school closures so far this school year, 96% of public schools have been able to remain open for full in-person learning.

According to the CDC, the continued focus on providing students with a safe environment for in-person learning is one of the main priorities for the CDC’s COVID-19 guidance, and can be best achieved by following a layered prevention strategy that includes both vaccination and masking.

While some have argued that face masks can hinder emotion recognition and interpersonal connection, and are bothersome in that they can muffle speech and fog up eyeglasses, still most argue that masking in schools is the correct thing to do.

“Overall, the benefits of masking really outweigh the potential risks of delays in social and language development,” said Michelle Durham, MD, MPH, a clinical associate professor of psychiatry at Boston University School of Medicine and a physician specializing in pediatric and adult psychiatry at Boston Medical Center.

Tina Tan, MD, an attending physician in the Division of Infectious Diseases at Ann & Robert H. Lurie Children’s Hospital of Chicago, and a professor of pediatrics at Northwestern University Feinberg School of Medicine, said she absolutely agreed with the CDC guidance that recommends masking in schools. “We know that masking in addition to other protective mitigation protocols works to decrease transmission and spread of COVID-19,” she said. “Masking in schools is also important because the majority of children in the K-12 space are not vaccinated; there remain many teachers and staff who are not vaccinated; and the COVID-19 delta variant continues to circulate in the community,” and omnicron cases are increasing.

“There is very strong evidence that masks reduce the transmission of not only COVID-19, but also other respiratory viruses in children,” Dr. Tan added. “States that do not have mask mandates in schools have higher rates of COVID cases in the overall population and in the school setting than those that have mask mandates in place.”

Dr. Tan said the COVID-19 delta variant is different from other variants in that it is significantly more transmissible. “COVID infection in children tends to be milder with cough and fever being the most common symptoms, and [children] are less likely to die compared with adults. However, children can become severely ill with COVID, especially those younger than 24 months of age, children with underlying conditions, and Black and Latino children. Because of the increased transmissibility and the significant increase in the number of children infected, this has resulted in a significant increase in children requiring hospitalization for their COVID disease.”

Some people have questioned whether continuous use of face masks by teachers and other adults may harm their children’s speech and language development, the American Academy of Pediatrics (AAP) points out that visually impaired children develop speech and language skills at the same rate as their peers. According to the AAP, there is no known evidence that use of face masks interferes with speech and language development or social communication. Plus, the AAP argued, children can still get plenty of face time at home with mask-free family members.

According to a study by psychologists at the University of Wisconsin-Madison, the proliferation of face coverings to keep COVID-19 in check isn’t keeping kids from understanding facial expressions. The study concluded that children were still able to make accurate inferences about emotions, even when parts of the faces were covered, and that masks are unlikely to dramatically impair children’s social interactions in their everyday lives. Other studies have shown a shift has occurred in how people perceive faces such that the more people are interacting with others who are wearing masks, the more they have learned to focus on visual cues from the eye area of the face.

The United States differs from England in that most children in England are not mandated to wear masks. It has been argued that one reason that Britain can take such risks is nearly all adults older than 65—a high-risk population—have been fully vaccinated and this is not the case in the United States. One of the biggest reasons for masking children is their possibility of infecting high-risk populations. “The benefits of masking up protect a lot of people in the community, in the family, and in any of the places we are going, and that is a good thing to do from a public health standpoint. The consequence of not masking can be very deadly as we have seen over the course of the pandemic,” Dr. Durham said. In England, cases surged this fall and are surging again this winter, more so the United States and many other countries.