Wearing facemasks amid the COVID-19 pandemic has proven effective in preventing transmission and subsequently saving lives. However, the US population has showcased a varying degree of willingness to wear facemasks in the interest of helping prevent the spread of COVID-19. The purpose of this surveillance study is to report changes in mask use over time in vaccinated and unvaccinated participants from the COVID-19 Community Research Partnership  (CRP). This study included participants 18 years and older, enrolled by December 2020 (when COVID-19 vaccination first became available in the United States), who completed daily surveys about five times each month, December 2020 through August 2021.


Daily online email or text surveys asked about COVID-19 exposures, symptoms, and mask use to subjects who were also asked to report any prior COVID-19 illness, age group, sex, race/ethnicity, and healthcare worker occupation. Subjects responded to these surveys with direct Yes/No answers. The rate of mask use was calculated as the proportion of daily responses per day and per week. This data was then compared to reported vaccination status in order to establish any connections between them and reported activity by subjects.


The resulting data demonstrates a consistent association between mask use and vaccination status. The relatively stable rate of reported interactions outside the household indicates that mask use changed independently of interactions outside the household. Although mask use declined on weekends and holidays, use remained higher among vaccinated participants. Higher mask use among those vaccinated earlier might reflect higher mask use among healthcare workers and those aged ≥65 years who became eligible for vaccination before other groups.