KFF COVID-19 Vaccine Monitor: April 2021

This KFF COVID-19 Vaccine Monitor was designed and analyzed by public opinion researchers at the Kaiser Family Foundation (KFF). The survey was conducted April 15-29, 2021, among a nationally representative random digit dial telephone sample of 2,097 adults ages 18 and older (including interviews from 778 Hispanic adults and 507 non-Hispanic Black adults), living in the United States, including Alaska and Hawaii (note: persons without a telephone could not be included in the random selection process). Phone numbers used for this study were randomly generated from cell phone and landline sampling frames, with an overlapping frame design, and disproportionate stratification aimed at reaching Hispanic and non-Hispanic Black respondents. Stratification was based on incidence of the race/ethnicity subgroups within each frame. Specifically, the cell phone frame was stratified as: (1) High Hispanic: Cell phone numbers associated with rate centers from counties where at least 35% of the population is Hispanic; (2) High Black: Cell phone numbers associated with remaining rate centers from counties where at least 35% of the population is non-Hispanic Black; (3) Else: numbers from all remaining rate centers. The landline frame was stratified as: (1) High Black: landline exchanges associated with Census block groups where at least 35% of the population is Black; (2) Else: all -remaining landline exchanges. The sample also included 163 respondents reached by calling back respondents that had previously completed an interview on the KFF Tracking poll at least nine months ago. Another 358 interviews were completed with respondents who had previously completed an interview on the SSRS Omnibus poll (and other RDD polls) and identified as Hispanic (n = 221; including 67 in Spanish and 40 who screened as potentially undocumented) or non-Hispanic Black (n=137). An oversample of potentially undocumented Hispanic (n=32) respondents was reached by dialing prepaid cell phone number in the High Hispanic stratum and screening for potential residency status. Computer-assisted telephone interviews conducted by landline (298) and cell phone (1,799, including 1,411 who had no landline telephone) were carried out in English and Spanish by SSRS of Glen Mills, PA. To efficiently obtain a sample of lower-income and non-White respondents, the sample also included an oversample of prepaid (pay-as-you-go) telephone numbers (25% of the cell phone sample consisted of prepaid numbers) Both the random digit dial landline and cell phone samples were provided by Marketing Systems Group (MSG). For the landline sample, respondents were selected by asking for the youngest adult male or female currently at home based on a random rotation. If no one of that gender was available, interviewers asked to speak with the youngest adult of the opposite gender. For the cell phone sample, interviews were conducted with the adult who answered the phone. KFF paid for all costs associated with the survey.