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NCT Number: NCT05271669

COVID-19 Immunity and 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.

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Key information

Conditions

COVID-19 Coronaviridae Infections Coronavirus Infections Infections Lung Diseases Nidovirales Infections Pneumonia Pneumonia, Viral RNA Virus Infections Respiratory Tract Diseases Respiratory Tract Infections Virus Diseases

Sex eligibility

All sexes

Study type

Observational

Primary location

About this study

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.

Who can participate

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

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

Treatment and study plan

Primary outcomes

  1. Proportion of participants with COVID-19 protective immunity

    Time frame: 1 year

    Prevalence of SARS-CoV-2 spike antibody

  2. Proportion of participants with marker of past COVID-19 infection

    Time frame: 1 year

    Prevalence of SARS-CoV-2 nucleocapsid antibody

Sponsors and collaborators

Lead sponsor

Chinese University of Hong Kong

Other

Registry information

Official study title

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

Important dates

Study start
2022
Primary completion
2026
Study completion
2027
First posted
Mar 9, 2022
Registry last updated
Mar 18, 2026

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.

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