Pfizer-BioNTech COVID-19 Vaccine Effectiveness Study - Kaiser Permanente Southern California
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Phase
—
Status
Completed
Study type
Observational
Enrollment
1actual
Sites
1
Country
United States
Every value on this page is a field the sponsor filed with ClinicalTrials.gov, reproduced. Dates are their own estimates, revised as a study runs, unless the registry marks them actual. sources →
Source: ClinicalTrials.gov, retrieved 2026-08-19
Dates
each axis at the precision it was filed, with the registry's own basis| Date | Filed | Basis | What it is |
|---|---|---|---|
| Start | 2021-05-15 | actual | When the study began enrolling |
| Primary completion | 2025-04-30 | actual | The date the last participant is measured for the primary outcome — the readout window |
| Study completion | 2025-04-30 | actual | The whole study's end, after follow-up |
| First posted | 2021-04-19 | actual | When this record first appeared on the registry |
| Results posted | — | When the sponsor posted results to the registry | |
| Record updated | 2025-07-29 | actual | The sponsor's own last edit to this record — every projection above is as current as this date |
What it studies
Condition
- COVID-19
Interventions
- Biological: Primary Exposure Status of Pfizer-BioNTech COVID-19 Vaccine — also filed as COVID VACCINE
- Biological: BNT162b2 BA.4/5 bivalent
- Biological: XBB.1.5-adapted vaccinated
Primary outcomes
what the primary-completion date above is the date OFTest Negative Design Outcome: VE calculated as 1 minus the odds ratio (OR) comparing the odds of being vaccinated with 2 doses with BNT162b2 for hospitalized cases and controls, multiplied by 100%.
measured up to three years
Cohort Design Outcome: VE calculated as 1 minus the hazard ratio (HR) comparing the incidence of 2 doses with BNT162b2 for hospitalization due to SARS-CoV-2 infection and not, multiplied by 100%.
measured up to three years
VE of XBB.1.5-adapted monovalent vaccine against hospitalization
measured up to three years
VE of XBB.1.5-adapted monovalent vaccine against critical illness
measured up to three years
VE of XBB.1.5-adapted monovalent against outpatient visits
measured up to three years
VE of XBB.1.5-adapted monovalent vaccine against UC/ED visits.
measured up to three years
Publications
- PMID 37898148 — linked by the registry
- PMID 36216013 — linked by the registry
- PMID 35468336 — linked by the registry
- PMID 34619098 — linked by the registry
Linked on the registry record. A “linked by the registry” entry is NLM's own automated PubMed match, not a claim by the sponsor that the paper reports this study.
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