Recruiting

Immunization Messages

Sponsor:

Kaiser Permanente

Code:

NCT07838038

Conditions

Covid-19 Vaccination

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Accepted

Interventions

Vaccine choice message

Vaccine choice + platform-framed message

Vaccine choice + HCP trust-framed message

Vaccine choice + reactogenicity-framed message

Study Details

Brief summary:

COVID-19 vaccination among patients at high risk for severe disease has declined in the United States since 2022. Prior research, including discrete choice experiments (DCEs), has demonstrated that vaccine preferences are influenced by attributes such as effectiveness, safety, convenience, and protection against severe disease. Although DCEs provide valuable insights into stated vaccine preferences and decision-making, they rely on hypothetical scenarios and cannot directly assess how vaccine attributes influence real-world vaccine uptake. Additional research is needed to understand the relationship between vaccine characteristics and observed COVID-19 vaccination behavior in routine clinical practice.

The EMPOWeR study is a pragmatic randomized controlled trial conducted within Kaiser Permanente Southern California (KPSC) to evaluate the effect of immunization messages and reminders that highlight COVID-19 vaccine choices on vaccine uptake. The primary research questions are:

1. Does having a choice in COVID-19 vaccine platform affect vaccine uptake among patients at high-risk of severe disease? 1a. Does having a choice in COVID-19 vaccine platform affect vaccine uptake among patients at high-risk of severe disease, when differences in vaccine platform are highlighted? 1b. Does having a choice in COVID-19 vaccine platform affect vaccine uptake among patients at high-risk of severe disease, when a trusted healthcare professional (HCP) endorses both vaccine options? 1c. Does having a choice in COVID-19 vaccine platform affect vaccine uptake among patients at high-risk of severe disease, when vaccine reactogenicity is highlighted?

A secondary research question is:
2. Does having a choice in COVID-19 vaccine additionally increase uptake of influenza vaccine?

During the 2026-2027 respiratory virus season, eligible KPSC members who are at high-risk of severe COVID-19 will be randomly assigned to receive a standard reminder message or a reminder message with additional information about available COVID-19 vaccine options.

Conditions

Covid-19 Vaccination

Study ID

NCT07838038

Start date

Sep 29, 2026

Status verified date

Sep, 2026

Completion date

Jun 30, 2027

Anticipated

Primary completion date

Jan 31, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Accepted

Inclusion Criteria:

  • Aged ≥18 years;
  • Active KPSC member;
  • Continuous membership from 27 August 2025 to 28 September 2026;
  • Members who are aged 65 years and older, or adults aged 18-64 years with at least one of the following health conditions that increases their risk for severe COVID-19 illness, including: a) asthma, b) cancer, c) ischemic stroke, d) intracerebral or subarachnoid hemorrhage, e) transient ischemic attack, f) chronic kidney disease, g) dialysis, h) bronchiectasis, i) chronic obstructive, pulmonary disease (COPD), j) pulmonary fibrosis, k) cystic fibrosis, l) pulmonary hypertension, m) cirrhosis, n) non-alcoholic fatty liver disease (NALD), o) alcoholic liver disease, p) autoimmune hepatitis, q) diabetes, r) heart failure, s) coronary artery disease, t) cardiomyopathy, u) HIV, v) obesity, w) essential hypertension, x) primary immunodeficiency and other underlying immunocompromising conditions, y) solid organ or blood stem cell transplant, z) tuberculosis;
  • No documented receipt of updated 2026-27 COVID-19 vaccine as of 28 September 2026;
  • Has valid email information.

Exclusion Criteria:

  • Unable to receive or opted out of email communication.
  • People with unknown or missing sex.
  • People who cannot safely receive a COVID-19 vaccine, including those who had a severe allergic reaction to a previous COVID-19 vaccine or have a contraindication to COVID-19 vaccine or a vaccine ingredient, will not be included in the study.
  • People with metastatic or terminal illness, advanced illness, receiving hospice or palliative care, or resident in skilled nursing facilities.
  • People who are pregnant or currently breastfeeding.

Study Design

Enrollment

1300000 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Health Services Research

Interventions and Outcome Measures

Arms

no intervention: Usual Care

Standard COVID-19 vaccination reminder message sent as part of usual care.

experimental: A. Choice-framed

Intervention arm tests the effects of choice-framed communication to increase patient's awareness of their available choices of COVID-19 vaccines, compared with usual care.

experimental: B. Choice + vaccine platform-framed

Intervention arm tests the effects of choice-framed communication to increase patients' awareness of their available choices of COVID-19 vaccines AND explain differences in vaccine composition and mechanisms of protection by vaccine type, compared with usual care.

experimental: C. Choice + HCP trust-framed

Intervention arm tests the effects of choice-framed communication to increase patients' awareness of their available choices of COVID-19 vaccines AND emphasizes the support of healthcare personnel (HCP) for both vaccine options, compared with usual care.

experimental: D. Choice + reactogenicity-framed

Intervention arm tests the effects of choice-framed communication to increase patients' awareness of their available choices of COVID-19 vaccines AND information about expected side effects, compared with usual care.

Interventions

Vaccine choice message

A message communicating available choices of COVID-19 vaccines.

Vaccine choice + platform-framed message

A message communicating available choices of COVID-19 vaccines and differences in vaccine composition and mechanisms of protection by vaccine type.

Vaccine choice + HCP trust-framed message

A message communicating available choices of COVID-19 vaccines and emphasizes the support of healthcare personnel (HCP) for both vaccine options.

Vaccine choice + reactogenicity-framed message

A message communicating available choices of COVID-19 vaccines and expected side effects of available vaccines.

Primary outcome measure

  • Proportion of participants with documented receipt of the updated 2026-27 COVID-19 vaccine [ Time Frame: up to 4 months after intervention ]

Central Contacts and Locations

Central contacts

Annette Regan, PhD

626-760-2482annette.k.regan@kp.org

Zendi S Yha, BS

626-372-5637zendi.s.yha@kp.org

Locations

Kaiser Permanente Southern California, Department of Research & Evaluation

Recruiting

Pasadena, California, United States, 91101

Contacts

Zendi S Yha, BS

626-372-5637zendi.s.yha@kp.org

Annette Regan, PhD, MPH

626-760-2482annette.k.regan@kp.org

More Information

Sponsor

Kaiser Permanente

Last update posted

Oct 15, 2026

Last verified

Sep, 2026

Keywords

  • COVID-19 Vaccination
  • COVID-19 Vaccine Uptake
  • Vaccine Choice
  • Behavioral Intervention
  • High-Risk Adults
  • Patient Preference
  • Pragmatic Trial
  • Implementation Science
  • Health Services Research

Trial information was received from ClinicalTrials.gov and was last updated on 2026-10-16. This information was provided to ClinicalTrials.gov by Kaiser Permanente on 2026-10-15. Recruitment status is synced daily from ClinicalTrials.gov and may not reflect the sponsor's current status. Confirm during your call.