The text labels below the timeline and in the right upper corner represent the ABCD COVID-19 surveys and assembled external data sets, respectively. The text above the timeline represents selected federal- and state-level responses. Adult vaccination rollout occurred on December 13, 2020. The ABCD COVID-19 Rapid Response Research consisted of online surveys disseminated on May 16 to May 22, 2020 (n = 7240, survey 1), June 24 to June 27, 2020 (n = 7554, survey 2), August 4 to August 5, 2020 (n = 6852, survey 3), October 8, 2020 (n = 6688, survey 4), December 13, 2020 (n = 6068, survey 5), and March 2, 2021 (n = 5929, survey 6). Because the surveys did not restrict expiration date, participants could complete the surveys on different dates other than the distribution dates. The last completed questionnaire was returned on April 24, 2021 (Figure 2; eMethods 1 and 2 in the Supplement). CDC indicates US Centers for Disease Control and Prevention; JHU, Johns Hopkins University.