COVID-19 Immunity and Changes Over Time

March 16, 2026 updated by: Shui-Shan Lee, MD, Chinese University of Hong Kong

Patterns of SARS-CoV-2 Immunity at Household Level and Their Changes Over Time

The risk of household spread of SARS-CoV-2 hinges on both the transmission dynamics of the virus circulating in the community as well as the seroprotection pattern of constituent members, which can be attributed to vaccination and previous infections. This study is conceptualised to assess the dynamicity of SARS-CoV-2 risk at the household level, through monitoring the pattern of seroprotection, in conjunction with the vaccination coverage, history of infection and exposure risk in the setting of Hong Kong.

Study Overview

Status

Recruiting

Conditions

Detailed Description

The aim of this study is to assess the SARS-CoV-2 risk at the household level, with the objectives of (a) determining the coverage of vaccination and its changes over time; (b) monitoring pattern of exposure and history of infection; and (c) evaluating the level of seroprotection and its longitudinal trend.

A cohort of households comprising 900 persons would be recruited. Invited participants would be attend the Research Centre for blood sampling and the completion of a simple questionnaire at 3 different timepoints at 12-18 months apart. A questionnaire would be administered to capture the following characteristics: (a) Socio-demographics; (b) History of SARS-CoV-2 infection; (c) adoption of precautionary measures; (d) SARS-CoV-2 testing history and (e) SARS-CoV-2 vaccination uptake.

Participants would be tested for SARS-CoV-2 serology. The main markers for measurement are nucleocapsid antibody for inferring past infection, spike antibody for the immunological responses, and seroprotection by SARS-CoV-2 surrogate virus neutralisation test.

Study Type

Observational

Enrollment (Estimated)

1350

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • China
    • HONG KONG
      • Hong Kong, HONG KONG, China, 0000
        • Recruiting
        • Shui Shan Lee
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Probability Sample

Study Population

Adults of households enrolling in a population cohort covering residents from all 18 districts in Hong Kong.

Description

Inclusion Criteria:

  • adults of age 18 or above, or children under the age of 18 with informed consent of the legal guardian
  • normally residing in Hong Kong
  • could communicate in spoken and written Chinese and/or English

Exclusion Criteria:

  • individuals with mental illness
  • prisoners

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: Cohort
  • Time Perspectives: Prospective

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Proportion of participants with COVID-19 protective immunity
Time Frame: 1 year
Prevalence of SARS-CoV-2 spike antibody
1 year
Proportion of participants with marker of past COVID-19 infection
Time Frame: 1 year
Prevalence of SARS-CoV-2 nucleocapsid antibody
1 year

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Chinese University of Hong Kong

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 6, 2022

Primary Completion (Estimated)

July 1, 2026

Study Completion (Estimated)

January 1, 2027

Study Registration Dates

First Submitted

March 7, 2022

First Submitted That Met QC Criteria

March 7, 2022

First Posted (Actual)

March 9, 2022

Study Record Updates

Last Update Posted (Actual)

March 18, 2026

Last Update Submitted That Met QC Criteria

March 16, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • Protocol HK COVID cohort 2021

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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