“…Household transmission occurs rapidly after an index case introduces the infection and with high household attack rates, can originate from both children and adults 19 , and are associated with high rates of hospitalization and death. 2,5,6 Early in the US pandemic, even when mask use was recommended and became the norm outside the home, and even in areas where stay at home orders had been put in place, mask use inside the home or other at-home risk mitigation measures were not recommended except in situations where there were ill/infected persons (when 10-14 days of isolation using a separate bedroom and bathroom was recommended to reduce household transmission). However, because of household crowding, a lack of space in the households, or a need to go to work, provide childcare, or care for other household/family measures, isolation of ill/infected persons and quarantine of those who have had a high risk exposure (e.g., to a confirmed case) is not always feasible, and other risk mitigation measures (e.g., mask wearing, opening windows) are therefore needed.…”