KFF COVID-19 Vaccine Monitor: Concerns And Precautions Among Adults Who Report A Weakened Or Compromised Immune System

This KFF COVID-19 Vaccine Monitor Poll was designed and analyzed by public opinion researchers at the Kaiser Family Foundation (KFF). The survey was conducted July 7 – 17, 2022, online and by telephone among a nationally representative sample of 1,847 U.S. adults. Interviews were conducted in English (n=1760) and in Spanish (n=87). The sample includes 1,585 adults reached through the SSRS Opinion Panel either online (n=1545) or over the phone (n=40), including an oversample of parents with a child under age 5 (n=471) and parents with a child in another age group (n=757). The SSRS Opinion Panel is a nationally representative probability-based panel where panel members are recruited randomly in one of two ways: (a) Through invitations mailed to respondents randomly sampled from an Address-Based Sample (ABS) provided by Marketing Systems Groups (MSG) through the U.S. Postal Service’s Computerized Delivery Sequence (CDS); (b) from a dual-frame random digit dial (RDD) sample provided by MSG. For the online panel component, invitations were sent to panel members by email followed by up to 4 reminder emails.

Another 250 interviews were conducted from a random digit dial telephone sample of prepaid cell phone numbers obtained through MSG. Phone numbers used for the prepaid cell phone component were randomly generated from a cell phone sampling frame with disproportionate stratification aimed at reaching Hispanic and non-Hispanic Black respondents. Stratification was based on incidence of the race/ethnicity groups within each frame. The sample also included 12 respondents reached by calling back respondents that had previously completed an interview on the KFF Tracking poll.

The combined cell phone and panel samples were weighted to match the sample’s demographics to the national U.S. adult population using data from the Census Bureau’s 2021 Current Population Survey (CPS). Weighting parameters included sex, age, education, race/ethnicity, region, and education. The sample was also weighted to match patterns of civic engagement from the September 2017 Volunteering and Civic Life Supplement data from the CPS. The sample was also weighted to match frequency of internet use from the National Public Opinion Reference Survey (NPORS) for Pew Research Center.  The weights take into account differences in the probability of selection for each sample type (prepaid cell phone and panel). This includes adjustment for the sample design and geographic stratification of the cell phone sample, within household probability of selection, and the design of the panel-recruitment procedure.

The margin of sampling error including the design effect for the full sample is plus or minus 4 percentage points. Numbers of respondents and margins of sampling error for key subgroups are shown in the table below. Sample sizes and margins of sampling error for other subgroups may be higher and are available by request. Sampling error is only one of many potential sources of error and there may be other unmeasured error in this or any other public opinion poll. KFF public opinion and survey research is a charter member of the Transparency Initiative of the American Association for Public Opinion Research.