COVID-19 Antibody and Reinfection Study

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.

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Key information

Conditions

COVID-19 Testing

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

Kaiser Permanente

Aurora, Colorado, 80014, United States

About this study

In this study, the Kaiser Permanente Colorado (KPCO) Institute for Health Research (IHR) will evaluate SARS-CoV-2 IgG antibody titers over time among individuals with evidence of prior infection, and correlate antibody titers with risk of recurrent infection. The investigators will identify KPCO members who have and have not had prior infection, enroll them into a cohort study, conduct serial surveys for new COVID-19 symptoms, and facilitate serial viral and antibody testing.

All laboratory testing procedures and clinical management of participants will be conducted by KPCO operations. The research team will identify participants, obtain consent, administer surveys to assess COVID-19 symptoms, and direct patients to the appropriate testing. Health outcomes on cohort participants will be tracked with survey data on symptoms, clinical and utilization data from the KPCO electronic health record (e.g., hospitalization), and laboratory data (e.g., viral test results).

This research-operations partnership strategy will generate data to better understand the implications of positive antibody titers to this novel pathogen.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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.

Treatment and study plan

Primary outcomes

Reinfection With SARS-CoV-2

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

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.

Sponsors and collaborators

Lead sponsor

Kaiser Permanente

Other

Registry information

Important dates

Study start: 2020
Primary completion: 2023
Study completion: 2024
First posted: May 9, 2022
Registry last updated: Sep 18, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Published trials that share one or more normalized conditions with this study.

Completed