COVID-19 Antibody and Reinfection Study

NCT05365750 | Completed Results

• 1 other identifier: 1589316-19
• Study Type: observational
• Target: 4,235
• Locations: 1 country
• Sites: 1

Brief 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. 1.Quantify antibody titers among participants over 9 months.
2. 2.Determine the rates of asymptomatic, mild, and severe recurrent infection among participants with prior COVID-19.
3. 3.Examine association between antibody titer levels and risk of recurrent infection using a case control analysis nested in the cohort.

Conditions

COVID-19 Testing

Keywords

SARS-CoV-2

Outcome Measures

Primary Outcomes (1)

• Reinfection With SARS-CoV-2

  In this case-control analysis, case patients were participants with the outcome of reinfection. The date of reinfection was the index date. Control patients were those with a primary infection but without the outcome reinfection by the index date. The case and control participants were compared with respect to a seronegative test result (exposure) after primary infection and closest in time to the index date. Because the cases and controls were selected on the basis of the outcome, the seronegative result is listed below by case and control status.

  Through the completion of the study analytic period, an average of 6 months

Study Arms (2)

Case

Case patients were drawn from a random sample of individuals who were enrolled in KPCO's health plan had suspected or confirmed SARS-CoV-2 infection and a random stratified sample of the general KPCO membership with similar age, gender, race/ethnicity and co-morbidities as case group. Within the cohort, case patients had a SARS-CoV-reinfection, defined as a positive SARS-CoV-2 RNA test ≥ 90 days after the first positive RNA test.

Control

Control patients were drawn from a random sample of individuals who were enrolled in KPCO's health plan had suspected or confirmed SARS-CoV-2 infection and a random stratified sample of the general KPCO membership with similar age, gender, race/ethnicity and co-morbidities as case group. Within the cohort, control patients had no evidence of a SARS-CoV-reinfection during the period of interest.

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Probability Sample

Study Population

The study cohort will include individuals who are enrolled in Kaiser Permanente Colorado's health plan. Individuals will be selected who have evidence of prior SARS CoV-2 infection and random samples of the general KPCO membership of similar demographic characteristics who appear not to have had SARS CoV-2 infection.

Sponsors & Collaborators

• Kaiser Permanente: lead

Study Sites (1)

Kaiser Permanente

Aurora, Colorado, 80014, United States

Location

Related Publications (1)

• Binswanger IA, Narwaney KJ, Barrow JC, Albers KB, Bechtel L, Steiner CA, Ann Shoup J, Glanz JM. Association between severe acute respiratory syndrome coronavirus 2 antibody status and reinfection: A case-control study nested in a Colorado-based prospective cohort study. Prev Med Rep. 2023 Dec 1;37:102530. doi: 10.1016/j.pmedr.2023.102530. eCollection 2024 Jan.

  PMID: 38205171 RESULT

Related Links

• Publication

Limitations and Caveats

Adherence to the study's testing guidance was inconsistent. We encouraged regular on-site testing but may not have captured some home-based testing results. Variable sensitivity and specificity of different serologic tests could have influenced our results. Variable sero-reversion rates across tests could have been due to variable lengths of time between the primary infection and testing. The definition of a reinfection used could have identified viral persistence.

Results Point of Contact

• Title: Ingrid A Binswanger, MD, MPH
• Organization: Kaiser Permanente Colorado

ingrid.a.binswanger@kp.org

720-416-7104

Study Officials

• Ingrid Binswanger, MD, MPH, MS

  Kaiser Permanente

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: No

Study Design

• Study Type: observational
• Observational Model: CASE CONTROL
• Time Perspective: PROSPECTIVE
• Target Duration: 10 Months
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Senior Investigator

Study Record Dates

• First Submitted: May 5, 2022
• First Posted: May 9, 2022
• Study Start: June 15, 2020
• Primary Completion: March 30, 2023
• Study Completion: December 31, 2024
• Last Updated: September 18, 2025
• Results First Posted: September 18, 2025

Record last verified: 2025-08

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)