NCT05094635

Immunogenicity Against SARS-CoV-2 in COVID-19 Close Contacts

Characteristics of Immunogenicity Against SARS-CoV-2 in the Community With Home-quarantined Covid-19 Patients in Ho Chi Minh City, Vietnam

• Status: Unknown
• Phase: —
• Study type: Observational
• Enrollment: 772 (estimated)
• Sponsor: University of Medicine and Pharmacy at Ho Chi Minh City · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: —

Summary

This study will investigate the presence of SARS-CoV-2 neutralizing antibody and its association with demographic information, medical history of SARS-CoV-2 infected individuals, exposure history of close contacts, vaccination status, and compliance with the strategies for self-quarantine to prevent the transmission in the community where SARS-CoV-2 infected individuals were home-quarantined and treated.

Detailed description

In the 4th outbreak of the covid-19 pandemic in Ho Chi Minh City since 27 April 2021, asymptomatic or mild covid-19 patients were self-quarantined and treated at home. This home care setting could yield risk of SARS-CoV-2 transmission from the index cases to the people living surroundings. Therefore, this study will be performed to investigate the immunogenicity against SARS-CoV-2 in household members or people lived in the same municipality with home-quarantined covid-19 patients. All people over 18 years old, living in 2 blocks (V and Y) of Ngo Gia Tu apartment, which is located in District 10, Ho Chi Minh City, will be recruited into this study. A survey will be conducted using a questionnaire to collect the data related to the basic demographic information, medical history of SARS-CoV-2 infected individuals, exposure history of close contacts, vaccination status, and compliance with the strategies for self-quarantine to prevent the transmission in the community. At the time of recruitment, Covid-19 rapid antigen detection tests using nasopharyngeal swabs will be performed for all study subjects. In addition, a total of 5mL of intravenous blood samples will be collected for serum extraction and DNA isolation. SARS-CoV-2 neutralizing antibody levels in serum samples will be evaluated by a surrogate virus neutralization test by using NeutraLISA kit® (Euroimmun, Luebeck, Germany). DNA will be isolated and stored for further use in investigating the association of ACE2 genetic polymorphisms with the prevalence of SARS-CoV-2 neutralizing antibodies.

Conditions

• Covid19
• Vaccine Reaction

Interventions

Type	Name	Description
DIAGNOSTIC_TEST	SARS-CoV-2 IgG II Quant	3ml of blood samples are collected, contained in heparin-free tubes, and centrifuged. Blood serum samples are collected and stored at the -80 Celcius degree. SARS-CoV-2 IgG antibodies in human serum and plasma are detected using chemiluminescent microparticle immunoassay (CMIA) technology on the ARCHITECT I 1000r System. Quality Control procedures will take place once daily, with three levels: one negative control and two positive controls. Sample, SARS-CoV-2 antigen-coated paramagnetic microparticles, and assay diluent are combined and incubated. The SARS-CoV-2 IgG antibodies present in the sample bind to the antigen-coated microparticles. The resulting chemiluminescent reaction is measured as a relative light unit (RLU). There is a direct relationship between the titres of IgG antibodies to SARS-CoV-2 in the sample and the RLU detected by the system optics. Interpretation of Results: \< 50.0 AU/mL, Negative, ≥ 50.0 AU/mL, Positive

Timeline

• Start date: 2021-11-30
• Primary completion: 2021-12-31
• Completion: 2022-05-01
• First posted: 2021-10-26
• Last updated: 2021-11-01

Locations

1 site across 1 country: Vietnam