COVID-19(34) SARS-CoV-2(19) Epidemiology(14) Infection(12) Prevalence(11) estimate(10) random(10) Health(10) antibody(9) participant(9) Health Surveys(8) Pain(8) Epidemiologic methods(8) risk(8) medical records(8) surveillance.(8) Risk factors.(8) Health care seeking behavior(8) population surveillance(8) Follow-up(8) determine(8) herpes zoster(8) IgG(7) COVID-19 infection(7) regression models(6) Behavior(6) venous(6) recruited(6) SARS-CoV-2 spike(6) San Francisco(6)