N/A
Completed N=1,114
COVID-19 Antibody and Reinfection Study
COVID-19 Testing
Source: ClinicalTrials.gov NCT05365750 ↗
Enrolled (actual)
1,114
Serious AEs
0.0%
Results posted
Sep 2025
Primary outcomePrimary: Reinfection With SARS-CoV-2 — 12; 77; 68; 957 Participants
Summary
The goal of this study is to establish a cohort of Kaiser Permanente Colorado (KPCO) members who have and have not had COVID-19 infection for serial antibody testing and PCR testing to:
1. Quantify antibody titers among participants over 9 months.
2. Determine the rates of asymptomatic, mild, and severe recurrent infection among participants with prior COVID-19.
3. Examine association between antibody titer levels and risk of recurrent infection using a case control analysis nested in the cohort.
Outcome Measures
| Outcome | Result | p-value |
|---|---|---|
| PRIMARY Reinfection With SARS-CoV-2 |
12; 77; 68; 957 | — |
Eligibility Criteria
Inclusion criteria are Kaiser Permanente Colorado health plan members, with a valid email address or phone number in the electronic health record and not on the Do Not Call List for research.
Data sourced from ClinicalTrials.gov (NCT05365750). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication. Informational only — not medical advice.