Face coverings worn by children in school settings to reduce SARS-CoV-2 transmission

Oct. 13, 2021

A new report from ECRI, focuses on the effectiveness of nonmedical face masks to reduce SARS-CoV-2 transmission in children in school settings.

COVID-19 spreads rampantly in prolonged-interaction settings in the absence of public health measures (i.e., masking, social distancing, good hand hygiene). Researchers reviewed 18 publications providing evidence to assess the effectiveness of nonmedical face masks worn by children to reduce COVID-19 spread in schools (PreK to grade 12).

Five epidemiologic studies reported COVID-19 cases and SARS-CoV-2 transmission among students is relatively rare in schools that implement mask wearing and other mitigation strategies (e.g., physical distancing, handwashing, small class size). Several studies that constructed simulation models to assess SARSCoV-2 transmission in school settings with and without masks and additional mitigation strategies provide indirect but consistent evidence indicating face mask use by children has the potential to reduce transmission in schools.

In addition, 13 clinical and public health guidance documents were identified, including from CDC, the American Academy of Pediatrics (AAP), and the World Health Organization (WHO), that state children wearing nonmedical face masks in school settings can reduce SARS-CoV-2 transmission. Rationale: Public health measures remain the most effective measures, in addition to vaccines for people who are vaccine-eligible, for curbing SARS-CoV-2 transmission and COVID-19-related morbidity and mortality. Epidemiologic studies reported data from schools that implemented bundled mitigation strategies, which makes it difficult to attribute outcomes solely to masks.

The research discovered evidence gaps. Studies did not account for all SARS-CoV-2 variants. Studies are needed that directly or indirectly compare face mask effectiveness for reducing COVID-19 infections and stratify findings by school levels (i.e., elementary, middle school, high school). Three simulation studies assumed face mask effectiveness between 15% and 35%, which can vary by location and over time; simulation studies provide indirect evidence predicated on model inputs. Surveys collected data from five countries and may not generalize across populations or countries

Cloth face coverings or masks are reusable, washable, and made of different fabric types that are not standardized or intended for medical purposes. In its guidance for preventing COVID-19 in schools, the Centers for Disease Control and Prevention (CDC) recommends universal indoor masking for all students under 2 years old, regardless of vaccination status. CDC also recommends face coverings should be well-fitting and cover the nose, mouth, and chin.

Face masks, used in addition to other public health measures (i.e., hand hygiene, social distancing, and vaccination as age permits), are intended to reduce SARS-CoV-2 transmission among children and the public during the COVID-19 pandemic.

Children can be infected with SARS-CoV-2 and become sick with COVID-19. Children with mild or suspected COVID-19 are managed at home to prevent transmission to others. Children with underlying conditions (obesity, diabetes, asthma) and those one year old or younger are at high risk for severe COVID-19 illness. Newborns are at high risk of developing severe COVID-19 because they have immature immune systems and smaller airways. However, children between 10 and 18 years old are at higher risk of developing COVID-19 compared with younger children.  Studies have reported that children and adolescents can transmit SARS-CoV2 effectively in household and community settings. Other studies also reported that SARS-CoV-2 loads in children are comparable or higher than those found in adults and have similar secondary infectious rates. Children, as well as adults, can transmit SARS-CoV-2 even when asymptomatic.

Combined with good hand hygiene and physical distancing (six feet or two meters or more), face coverings are intended to contain droplets that may emanate when an infected person speaks, sings, coughs, or sneezes (i.e., source control) to reduce the amount of infectious droplets dispersed in the air. Face coverings can be disposable or reusable and are made of different materials. Disposable face masks are made of multiple layers of nonwoven material, and some may contain a nose wire to improve fit. Cloth face masks are made of fabric, reusable, and washable. Cloth face masks have been constructed in different shapes (e.g., flatfold pleats, duckbill, folded with no sewing) and fabrics (e.g., cotton, silk, nylon, polyester, nonwoven materials such as polypropylene, or a combination of these). Cloth face masks may also have different layering sequences (single-, double-, or triple-layered) with or without some type of material used as a filter between layers.

Cloth face masks and nonmedical masks differ from N95 respirators’ construction and fit, and their CLINICAL EVIDENCE ASSESSMENT construction is not standardized or required to meet any specifications. The potential benefits of cloth face masks and nonmedical masks vary widely and depend on construction, materials, and fit. 

Commercial face masks for children are available in different kid-friendly designs and sizes. Homemade cloth masks have the advantage of providing better fit when they are designed for the children’s age and specific craniofacial characteristics and geometries. Children’s face masks should also be comfortable to wear. Various commercially available face masks incorporate designs that are intended to improve comfort, including lightweight masks, breathable fabrics, comfortable ear loops, and bendable nose pieces.

Good mask wearing practices by children can be reinforced at home to ensure mask effectiveness. Parents are encouraged to explain to their children why masks are to be used and to demonstrate correct mask etiquette. A Mayo Clinic article recommends parents wear masks at home for a few hours to teach correct mask etiquette to their children. Other strategies that can be used at home to teach and motivate correct mask use in children include allowing children to decorate their own face mask or select cartoon characters they like for their masks, providing masks for toys that can be used during playtime, and taking photos of family and friends wearing face masks.

ECRI report

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