Clinical trial NCT05094635: Immunogenicity Against SARS-CoV-2 in COVID-19 Close Contacts
Official title: Characteristics of Immunogenicity Against SARS-CoV-2 in the Community With Home-quarantined Covid-19 Patients in Ho Chi Minh City, Vietnam
Study type: OBSERVATIONAL
Overall status: UNKNOWN
Conditions: Covid19
Vaccine Reaction
Lead sponsor: University of Medicine and Pharmacy at Ho Chi Minh City
Sponsor class: OTHER
First posted: 2021-10-26
Enrollment: 772
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Observational model: COHORT
Time perspective: CROSS_SECTIONAL
Sampling method: NON_PROBABILITY_SAMPLE
Study population: People 18 years of age and older, who lived in 2 blocks (V and Y) of Ngo Gia Tu apartment, located in District 10, Ho Chi Minh City, Vietnam, from July to September 2021

Brief 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.

Eligibility criteria: Inclusion Criteria:

* People who lived in the two blocks (V and Y) of Ngo Gia Tu apartment, located in District 10, Ho Chi Minh City, Vietnam, from July to September 2021
* 18 years of age and older
* Ability to understand and willingness to sign a written informed consent document.

Exclusion Criteria:

* People who were diagnosed with primary or secondary immunodeficiencies induced by diseases or medical treatments (immunosuppressants, chemotherapy, radiation therapy, ect.)

Primary outcomes:
measure: SARS-CoV-2 anti-RBD IgG concentration
timeFrame: Up to 1 week after examination
Secondary outcomes:
Other outcomes:
Locations:
city: Ho Chi Minh City
country: Vietnam
facility: University of Medicine and Pharmacy
Study officials:
affiliation: Study Principal Investigator
name: Tuan D Tran, PhD
role: PRINCIPAL_INVESTIGATOR
References: