Fig. 1.

Temporal trends in the proportion of respondents self-reporting mask use. Left panel A: By vaccination status as of August 31, 2021, per day. Data shown are daily sample proportion. Right panel B: By month of first vaccine, smoothed by week. Data shown are sample proportion per week with 95% confidence intervals (calculated using standard normal approximation to the binomial distribution). Dashed reference lines drawn at March 8, 2021 (CDC Issues First Set of Guidelines on How Fully Vaccinated People Can Visit Safely with Others, 2021) and May 13, 2021 (COVID-19, 2021, Masks, 2021), and July 27, 2021, the dates corresponding to changes in CDC community masking guidance. Dotted reference lines are drawn at December 25, 2020 (Christmas Day) and April 4, 2021 (Easter Day).