A Look at DESE's Cited Sources: Footnote #19, #23, and #32 - Reduction of secondary transmission of SARS-CoV-2 in households by face mask use, disinfection and social distancing: a cohort study in Beijing, China

DESE Claim 1 (footnote #19): "[...]masks or face coverings are among the most critical components of risk reduction."

DESE Claim 2 (footnote #23): "Masks/face coverings protect the general public against COVID-19 infection, with a recent retrospective study estimating near 80% effectiveness in reducing COVID-19 transmission, especially when worn prior to symptom onset."

DESE Claim 3 (footnote #32): "For instance, in a study of household transmission in China, keeping at least three feet of distance was associated with one-fourth the number of transmissions."

Cited Source: Wang, Y., Tian, H., Zhang, L., Zhang, M., Guo, D., Wu, W., ... & Liu, B. (2020). Reduction of secondary transmission of SARS-CoV-2 in households by face mask use, disinfection and social distancing: a cohort study in Beijing, China. BMJ Global Health, 5(5), e002794. Available at https://gh.bmj.com/content/bmjgh/5/5/e002794.full.pdf

Peer Reviewed?: Yes

Study Methodology: "A retrospective cohort study of 335 people in 124 families"

Notes: This study looks at household face mask use as a risk reduction measure in families who have a member that is COVID-19 positive. "The study confirms the highest risk of transmission prior to symptom onset, and provides the first evidence of the effectiveness of mask use, disinfection and social distancing in preventing COVID-19." Masks were effective in reducing transmission. While household settings are different than schools, other evidence from outside of household settings also supports mask use.

Supports DESE Claim 1?: Yes.

Supports DESE Claim 2?: Yes.

Supports DESE Claim 3?: Yes.