An interventional study of Vaccine choice message and Vaccine choice + platform-framed message in Covid-19 Vaccination, sponsored by Kaiser Permanente. Recruiting at 1 site in United States. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-10-15.
Sponsored by Kaiser Permanente · Not applicable, Interventional, and Health services research
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:
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:
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.
The Effect of Messaging on Pragmatic Outcomes Within an Integrated Healthcare System: A Randomized Trial (EMPOWeR) study is designed to learn whether vaccine reminder messages that highlight a patient's choice of COVID-19 vaccines can help increase vaccine uptake among adults who are at higher risk for serious illness from COVID-19. The study will take place within KPSC, a large integrated health care system in southern California, and will use routine health care messages and reminders for updated COVID-19 immunization .
COVID-19 vaccination rates have declined since 2022, including among older adults and people with medical conditions that increase their risk of severe disease. Concerns about vaccine side effects, trust, and vaccine technologies may influence whether people choose to get vaccinated. The EMPOWeR study will evaluate whether providing information about vaccine choices can encourage individuals at higher risk of severe COVID-19 to receive an updated COVID-19 vaccine.
Adults who are eligible for a COVID-19 vaccine and who meet the study eligibility criteria will be included in the study. Eligible participants include adults enrolled for care at KPSC who are either 65 years of age or adults aged 18 to 64 years with certain health conditions that place them at increased risk for severe COVID-19 illness. Participants will not be asked to attend study visits or complete surveys. The study will use immunization data already collected in electronic health records as part of routine care.
Participants will be randomly assigned to one of five groups. One group will receive a standard COVID-19 vaccine reminder message currently used in routine care. The other four groups will receive messages that provide information about available COVID-19 vaccine options: mRNA and protein-based COVID-19 vaccines. These messages may:
All messages will be delivered to eligible participants in early October 2026 using the participant's usual communication preferred language (i.e., English or Spanish). Follow-up reminder messages will also be sent later in the vaccination season (in early December 2026).
The main goal of the study is to determine whether these different messages increase receipt of the updated 2026-2027 COVID-19 vaccine. Additional goals include type of COVID-19 vaccine received receipt of an influenza vaccine, receiving influenza and COVID-19 vaccines on the same day, and the time between the reminder message and COVID-19 vaccination.
The study is designed to reflect real-world clinical practice. Participants will continue to receive routine medical care, and all vaccines will be provided through standard care processes. Researchers will compare vaccination outcomes across the different message groups to determine which communication approach is most effective for increasing vaccination uptake among high-risk adults.
This study may help health care systems better understand how to communicate with patients about vaccine options and improve vaccination coverage among populations at increased risk for severe COVID-19 illness.
112 studies on the registry are indexed under Patient Preference; 28 are open to participants now.
This study's planned enrollment of 1,300,000 is above the median of 134 across 52 interventional studies indexed under Patient Preference.
Browse Patient Preference studies →Kaiser Permanente is the lead sponsor of 393 studies on the registry; 43 are open to participants now.
Of its 7 completed or terminated interventional studies of FDA-regulated products, 3 (43%) have results posted.
Counted across the registry records on this site, refreshed daily.
The criteria were revised on the registry on Sep 29, 2026. See what changed
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A “mini-stroke”: temporary stroke-like symptoms caused by reduced blood flow to part of the brain, spinal cord or eye, without signs of a new stroke on a scan.
Stroke symptoms need emergency care at once, even if they go away.
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
TIA (transient ischaemic attack)
A “mini-stroke”: temporary stroke-like symptoms caused by reduced blood flow to part of the brain, spinal cord or eye, without signs of a new stroke on a scan.
Stroke symptoms need emergency care at once, even if they go away.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
COPD
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Autoimmune disease
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Metastases
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Standard COVID-19 vaccination reminder message sent as part of usual care.
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.
Behavioral: Vaccine choice message
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.
Behavioral: Vaccine choice + platform-framed message
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.
Behavioral: Vaccine choice + HCP trust-framed message
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.
Behavioral: Vaccine choice + reactogenicity-framed message
A message communicating available choices of COVID-19 vaccines.
A message communicating available choices of COVID-19 vaccines and differences in vaccine composition and mechanisms of protection by vaccine type.
A message communicating available choices of COVID-19 vaccines and emphasizes the support of healthcare personnel (HCP) for both vaccine options.
A message communicating available choices of COVID-19 vaccines and expected side effects of available vaccines.
Proportion of participants with documented receipt of the updated 2026-27 COVID-19 vaccine
Kaiser Permanente Southern California's electronic health record tracks the type of vaccine, dose, and date each patient receives. Immunization data will be retrieved from participants' electronic health records to ascertain COVID-19 immunization status during the study period.
Time frame: up to 4 months after intervention
Type of COVID-19 vaccine received
The brand of COVID-19 vaccines received will be retrieved from participants' electronic health records to ascertain the type of COVID-19 immunizations received during the study period.
Time frame: up to 4 months after intervention
Receipt of the 2026-27 influenza vaccine
Influenza vaccines received will be retrieved from participants' electronic health records to ascertain influenza immunization status during the study period.
Time frame: up to 4 months after intervention
Co-administration of COVID-19 vaccine and influenza vaccine
The date of influenza and COVID-19 vaccines received will be retrieved from participants' electronic health records and used to ascertain the number of participants who received an influenza and COVID-19 vaccine on the same day.
Time frame: up to 4 months after intervention
Time to immunization (in days) with an updated 2026-27 COVID-19 vaccine
The date of COVID-19 immunization will be retrieved from the participants' electronic health records and used to determine the number of days between message transmission and vaccination.
Time frame: up to 4 months after intervention
Plan to share: No — The individual-level data that will be analyzed for this study will not be publicly available due to privacy concerns. Individual requests to access the study data can be made to the study PI.
No publications or documents are linked to this record.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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