SARS-CoV-2NCT05876377
Use and Effectiveness of COVID-19 Vaccines Using State Vaccine Registries and Insurance Claims Data
An observational study of SARS-CoV-2 and COVID-19, run by Pfizer at 1 site in United States.
Trial summary
This study aims to use vaccination information from state vaccine registries linked with HealthVerity insurance claims for the following: to measure how effective the Pfizer-BioNTech vaccine is at preventing post-COVID conditions. to understand characteristics of patients who are receiving COVID-19 vaccines. Read more about this study
- Who is it for?
- Ages 6 months and older
- Conditions the study is for
- SARS-CoV-2, COVID-19, Post-Acute COVID-19 Syndrome
- What is being tested?
- Pfizer-BioNTech COVID-19 mRNA vaccine
- Type of treatment
- Vaccines
- How many people
- 1 participants
- Where
- 1 siteUnited States
- Study dates
- 23 Oct 2023to 31 May 2026
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 6 months and older
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Study population: Patients will be sourced from HealthVerity and include patients who are enrolled in the claims database as well as recorded in contributing states' deidentified vaccine registries. Patients who will be followed for the PCC endpoint must be eligible to receive the licensed/authorized vaccine during the study period.
Who may be able to join
- Patients must meet all of the following criteria to be eligible for inclusion in the study:
- Patients are required to have a COVID-19 diagnosis on or after September 5, 2024 AND no later than August 26, 2025
- Patients in HealthVerity database and residing in California or Louisiana as of index date AND
- Have ≥1 year of pharmacy and medical enrollment in HealthVerity prior to cohort entry date, allowing for up to a 30-day gap in enrollment AND
- ≥18 years old as of index date AND
- Have resided only in their respective state (California or Louisiana) for ≥1 year prior to index date
Who cannot join
- Patients meeting any of the following criteria will not be included in the study:
- Patients who were immunocompromised from 1 year prior to cohort entry OR
- Patients who received any 2024-2025 formulation of the COVID-19 vaccine prior to authorization (22 August 2024) OR
- Patients who have discrepancies in sex and/or year of birth between HealthVerity claims and state immunization registry datasets OR
- Patients who had a prior diagnosis of COVID-19 ≤180 days preceding cohort entry OR
- Patients who received any 2024/2025 formulation of the COVID-19 vaccine within 0 to 13 days prior OR 0 to 29 days post index COVID-19 diagnosis (i.e., -13 to +29 days around the index date)
Show all 49Show fewer
- Aim 2:
- By Age, Bivalent (older children, adults)
- Patients must meet all of the following inclusion criteria to be eligible for inclusion in the study:
- Has medical and pharmacy enrollment in HealthVerity as of August 31, 2022
- And is age ≥12 years
- With 6 months of continuous medical and pharmacy enrollment before calendar index date
- And does not have evidence of moderate/severe immunocompromise as defined by CDC
- And has evidence of ≥2 doses of COVID-19 original vaccine formulation before the calendar index date
- And does not have original vaccine formulation within 2 months before calendar index date
- And does not have a pregnancy start date within 9 months before or any point after calendar entry
- And does not have discrepancies in sex and/or year of birth between HealthVerity claims and state Immunization registry datasets.
- This analysis will be stratified by age: 12-17, 18-49. 50-64, 65-74, 75+, which will be measured as of August 31, 2022.
- By Age, Bivalent (younger children)
- Patients must meet all of the following inclusion criteria to be eligible for inclusion in the study:
- Has medical and pharmacy enrollment in HealthVerity as of 12 October 2022
- And is age 5-11 years
- With 6 months of continuous medical and pharmacy enrollment before calendar index date
- And does not have evidence of moderate/severe immunocompromise as defined by CDC
- And has evidence of ≥2 doses of COVID-19 original vaccine formulation before the calendar index date
- And does not have original vaccine formulation within 2 months before calendar index date.
- By Age, Bivalent (youngest children)
- Patients must meet all of the following inclusion criteria to be eligible for inclusion in the study:
- Has medical and pharmacy enrollment in HealthVerity as of 08 December 2022
- And is age 6 months-4 years
- With 6 months of continuous medical and pharmacy enrollment before calendar index date
- And does not have evidence of moderate/severe immunocompromise as defined by CDC
- And has evidence of ≥2 doses of COVID-19 original vaccine formulation before the calendar index date
- And does not have original vaccine formulation within 2 months before calendar index date.
- By Disease Status, Bivalent
- Patients must meet all of the following inclusion criteria to be eligible for inclusion in the study:
- Has medical and pharmacy enrollment in HealthVerity as of 31 August 2022
- And is age >=6 months
- And has continuous medical and pharmacy enrollment for 6 months before the calendar index date
- And has evidence of 1) moderate/severe immunocompromising condition or separately 2) COVID high-risk condition in a period before the calendar index period (lookback times are dependent on the disease and are provided in variable table below)
- And has evidence of ≥3 doses of COVID-19 original vaccine formulation before the calendar index date.
- For Pregnant Women, Bivalent
- Patients must meet all of the following inclusion criteria to be eligible for inclusion in the study:
- Has at least 6 months of medical and pharmacy enrollment in HealthVerity as of 31 August 2022
- And is female sex
- Aged 12-49
- And has estimated date of pregnancy start date within 9 months before or any point after the calendar entry date (determined using gestational age algorithm)
- And has evidence of ≥2 doses of COVID-19 original vaccine formulation before the pregnancy start date or 31 August 2022, whichever is latest.
- And did not receive the bivalent dose prior to pregnancy, if estimated pregnancy start date is after 31 August 2022
Trial locations and contacts
1 site in 1 country.
About this study
Official title: USE AND EFFECTIVENESS OF COVID-19 VACCINES USING STATE VACCINE REGISTRIES AND INSURANCE CLAIMS DATA
This study aims to use vaccination information from state vaccine registries linked with HealthVerity insurance claims for the following:
- to measure how effective the Pfizer-BioNTech vaccine is at preventing post-COVID conditions.
- to understand characteristics of patients who are receiving COVID-19 vaccines.
All patients whose information is kept unidentified in the HealthVerity database are eligible to be included for both aims of this study.
Read the detailed description
The vaccine effectiveness (VE) of BNT162b2 COVID-19 vaccine (e.g. KP.2 monovalent formulation) in preventing post-COVID health conditions will be assessed (Aim 1). This aim will utilize a retrospective cohort time-to-event design and evaluate the VE among vaccine-eligible patients from when the vaccine was authorized or approved (specified by age group) through the most current data available. Patients will be sourced from HealthVerity and includes patients who are enrolled in the claims database; data from the state's deidentified vaccine registry will be used to supplement claims data. Patients who will be followed for the PCC endpoint must be eligible to receive the vaccine during the study period. Comparisons between the vaccinated and vaccine eligible but unvaccinated (i.e., no receipt of the most recent formulation) groups will be made using descriptive statistics, incidence rates, and hazard ratios.
The second part of the study (Aim 2) will use a retrospective cohort design to describe the uptake of the vaccine in specific groups over time. Subjects will be identified through three different methods: 1) by analyzing all available dosing records in the Immunization Registry, 2) by using HealthVerity claims data based on specific calendar time periods when the vaccine was available, or 3) based on the start of pregnancy that occurs after EUA date. Patients will be followed until experiencing the vaccination under study, disenrollment, end of data or death. Vaccinations will be assessed overall and also by specific type of prior dose (mRNA vs other).
- Conditions
- SARS-CoV-2, COVID-19, Post-Acute COVID-19 Syndrome
- Being tested
- Pfizer-BioNTech COVID-19 mRNA vaccine
- Keywords
- COVID-19 Vaccines, COVID-19 Drug Treatment
- Medical subject headings
- COVID-19, Post-Acute COVID-19 Syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Pfizer-BioNTech COVID-19 mRNA vaccineBiological
Also called Pfizer-BioNTech COVID-19 Vaccine
Pfizer-BioNTech COVID-19 Vaccine, is FDA licensed or authorized under Emergency Use Authorization (EUA) for active immunization to prevent coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in individuals 6 months of age and older.
| Study group | Role | What they receive |
|---|---|---|
| 2024/2025 COVID-19 Unvaccinated (unexposed) | Did NOT receive any 2024/2025 formulated COVID-19 vaccine dose at least 14 days prior to COVID-19 diagnosis. | |
| KP.2 Vaccinated (exposed) | ≥14 days since receipt of Pfizer/BioNTech KP.2 dose prior to COVID-19 diagnosis Receives: Biological: Pfizer-BioNTech COVID-19 mRNA vaccine |
What is being measured
The primary outcome is the main question the study is designed to answer.
Aim 1: Any PCC-related diagnosis not present before the COVID-19 diagnosis
The primary endpoint is any PCC-related diagnosis as defined by Xie et al. (2024, NEJM) that occurs between 30 and 180 days following a COVID-19 diagnosis and was not present before the COVID-19 diagnosis. The primary endpoint will also be stratified by specific organ system / disease domains (cardiovascular; coagulation and hematologic; fatigue; gastrointestinal; kidney; mental health; metabolic; musculoskeletal; neurologic; and, pulmonary). All patients are required to have a diagnosis of COVID-19 (ICD-10-CM code = U07.1) as a predicating event for the subsequent evaluation of a PCC episode. The first 30 days after the diagnosis of COVID-19 will be excluded from the evaluation of a PCC episode as the acute infection period. The evaluation of the PCC episode will begin on Day 30 after the date of acute COVID-19 diagnosis through day 180.
Measured: 30-180 days after COVID-19 diagnosis
Aim 2: Number of patients with a COVID-19 vaccination
Any record of COVID-19 vaccination as recorded in the state immunization registry.
Measured: Date of vaccine authorization through the end of the corresponding respiratory season
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 May 2023
- Study start23 Oct 2023
- Primary completion31 May 2026
- Study completion31 May 2026
Why it stopped: Study discontinued due to questions of data validity and bias in data which would limit causal inference and estimation of vaccine effectiveness.
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for SARS-CoV-2Studies of the same condition, open and under way.
- More trials run by PfizerThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Retrospective
- Enrolment
- 1 participants (actual)
Sponsor and investigators
- Lead sponsor
- Pfizer
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Pfizer CT.gov Call Center, Study director, Pfizer
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05876377
- Sponsor's protocol ID
- C4591059
- Other IDs
- NCT05876377
- Status last verified
- Sep 2026
- First submitted
- 23 May 2023
- Last updated
- 15 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No: Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical\_trials/trial\_data\_and\_results/data\_requests.
Study at a glance
From the registry record, last updated by the sponsor on 15 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- USE AND EFFECTIVENESS OF COVID-19 VACCINES USING STATE VACCINE REGISTRIES AND INSURANCE CLAIMS DATA
- ClinicalTrials.gov ID
- NCT05876377
- Acronym / sponsor ID
- C4591059
- Conditions
- SARS-CoV-2, COVID-19, Post-Acute COVID-19 Syndrome
- Keywords
- COVID-19 Vaccines, COVID-19 Drug Treatment
- Study type
- Observational
- Recruitment status
- TerminatedReason stopped: Study discontinued due to questions of data validity and bias in data which would limit causal inference and estimation of vaccine effectiveness.
- Enrolment
- 1 participants (actual)
- Lead sponsor
- PfizerIndustry (pharma, biotech, devices)
- Study start
- 23 Oct 2023 (actual)
- Primary completion
- 31 May 2026 (actual)
- Study completion
- 31 May 2026 (actual)
- First posted
- 25 May 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study aims to use vaccination information from state vaccine registries linked with HealthVerity insurance claims for the following:
- to measure how effective the Pfizer-BioNTech vaccine is at preventing post-COVID conditions.
- to understand characteristics of patients who are receiving COVID-19 vaccines.
All patients whose information is kept unidentified in the HealthVerity database are eligible to be included for both aims of this study.
Detailed description
The vaccine effectiveness (VE) of BNT162b2 COVID-19 vaccine (e.g. KP.2 monovalent formulation) in preventing post-COVID health conditions will be assessed (Aim 1). This aim will utilize a retrospective cohort time-to-event design and evaluate the VE among vaccine-eligible patients from when the vaccine was authorized or approved (specified by age group) through the most current data available. Patients will be sourced from HealthVerity and includes patients who are enrolled in the claims database; data from the state's deidentified vaccine registry will be used to supplement claims data. Patients who will be followed for the PCC endpoint must be eligible to receive the vaccine during the study period. Comparisons between the vaccinated and vaccine eligible but unvaccinated (i.e., no receipt of the most recent formulation) groups will be made using descriptive statistics, incidence rates, and hazard ratios.
The second part of the study (Aim 2) will use a retrospective cohort design to describe the uptake of the vaccine in specific groups over time. Subjects will be identified through three different methods: 1) by analyzing all available dosing records in the Immunization Registry, 2) by using HealthVerity claims data based on specific calendar time periods when the vaccine was available, or 3) based on the start of pregnancy that occurs after EUA date. Patients will be followed until experiencing the vaccination under study, disenrollment, end of data or death. Vaccinations will be assessed overall and also by specific type of prior dose (mRNA vs other).
Study design
- Observational model
- Cohort
- Time perspective
- Retrospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| 2024/2025 COVID-19 Unvaccinated (unexposed) | – | –Did NOT receive any 2024/2025 formulated COVID-19 vaccine dose at least 14 days prior to COVID-19 diagnosis. |
| KP.2 Vaccinated (exposed) | – | Biological: Pfizer-BioNTech COVID-19 mRNA vaccine≥14 days since receipt of Pfizer/BioNTech KP.2 dose prior to COVID-19 diagnosis |
Who may qualify
- Ages
- 6 months and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
- Study population
- Patients will be sourced from HealthVerity and include patients who are enrolled in the claims database as well as recorded in contributing states' deidentified vaccine registries. Patients who will be followed for the PCC endpoint must be eligible to receive the licensed/authorized vaccine during the study period.
Key inclusion criteria (6 listed)
- Patients must meet all of the following criteria to be eligible for inclusion in the study:
- Patients are required to have a COVID-19 diagnosis on or after September 5, 2024 AND no later than August 26, 2025
- Patients in HealthVerity database and residing in California or Louisiana as of index date AND
- Have ≥1 year of pharmacy and medical enrollment in HealthVerity prior to cohort entry date, allowing for up to a 30-day gap in enrollment AND
- ≥18 years old as of index date AND
Key exclusion criteria (49 listed)
- Patients who were immunocompromised from 1 year prior to cohort entry OR
- Patients who received any 2024-2025 formulation of the COVID-19 vaccine prior to authorization (22 August 2024) OR
- Patients who have discrepancies in sex and/or year of birth between HealthVerity claims and state immunization registry datasets OR
- Patients who had a prior diagnosis of COVID-19 ≤180 days preceding cohort entry OR
- Patients who received any 2024/2025 formulation of the COVID-19 vaccine within 0 to 13 days prior OR 0 to 29 days post index COVID-19 diagnosis (i.e., -13 to +29 days around the index date)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Pfizer-BioNTech COVID-19 mRNA vaccineAlso: Pfizer-BioNTech COVID-19 VaccinePfizer-BioNTech COVID-19 Vaccine, is FDA licensed or authorized under Emergency Use Authorization (EUA) for active immunization to prevent coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in individuals 6 months of age and older. | Biological | KP.2 Vaccinated (exposed) |
Primary outcome
Aim 1: Any PCC-related diagnosis not present before the COVID-19 diagnosis
Time frame: 30-180 days after COVID-19 diagnosis
The primary endpoint is any PCC-related diagnosis as defined by Xie et al. (2024, NEJM) that occurs between 30 and 180 days following a COVID-19 diagnosis and was not present before the COVID-19 diagnosis. The primary endpoint will also be stratified by specific organ system / disease domains (cardiovascular; coagulation and hematologic; fatigue; gastrointestinal; kidney; mental health; metabolic; musculoskeletal; neurologic; and, pulmonary). All patients are required to have a diagnosis of COVID-19 (ICD-10-CM code = U07.1) as a predicating event for the subsequent evaluation of a PCC episode. The first 30 days after the diagnosis of COVID-19 will be excluded from the evaluation of a PCC episode as the acute infection period. The evaluation of the PCC episode will begin on Day 30 after the date of acute COVID-19 diagnosis through day 180.
Aim 2: Number of patients with a COVID-19 vaccination
Time frame: Date of vaccine authorization through the end of the corresponding respiratory season
Any record of COVID-19 vaccination as recorded in the state immunization registry.
Results and safety
The study was stopped early (reason given: Study discontinued due to questions of data validity and bias in data which would limit causal inference and estimation of vaccine effectiveness.). Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 15 Sep 2026.
- To obtain contact information for a study center near you, click here.Link provided by the sponsor.
- Individual participant dataSharing planned: No. Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical_trials/trial_data_and_results/data_requests.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Pfizer CT.gov Call Center study director
Pfizer
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of SARS-CoV-2 and COVID-19, run by Pfizer at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 49 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: stopped early, as of the sponsor's last update on 15 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study was stopped early (reason given: Study discontinued due to questions of data validity and bias in data which would limit causal inference and estimation of vaccine effectiveness.). Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Aim 1: Any PCC-related diagnosis not present before the COVID-19 diagnosis (time frame: 30-180 days after COVID-19 diagnosis). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 15 Sep 2026.