Effect of Inactivated SARS-CoV-2 Vaccines and ChAdOx1 nCoV-19 Vaccination to Prevent COVID-19 in Thai Households

Status

Active, not recruiting

Phases

Unknown

Study type

Observational

Source

TCTR

Registry ID

TCTR20211108003

Enrollment

208

Registered

2021-11-08

Start date

2021-05-01

Completion date

Unknown

Last updated

2026-08-03

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

The household transmission rate in index cases experienced the inactivated SARS-CoV-2 vaccines and ChAdOx1 nCoV-19 vaccination compared with unvaccinated. inactivated vaccine, SARS-CoV-2, COVID-19, ChAdOx1, household transmission

Interventions

Index cases that experienced inactivated SARS-CoV-2 Vaccines and ChAdOx1 nCoV-19 vaccination,Index cases that have no experienced inactivated SARS-CoV-2 Vaccines and ChAdOx1 nCoV-19 vaccination

Prevention,Prevention

Inactivated SARS-CoV-2 Vaccines and ChAdOx1 nCoV-19 Vaccinated index cases,Unvaccinated index cases

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: 1. SARS-CoV-2 PCR confirmed index cases 2. Index cases that has overall >/= 2 household members 3. Index cases must have high-risk contact with household members including contact in less than 6 feet distance at least 10 minutes in the last 14 days

Exclusion criteria

Exclusion criteria: 1. Index cases who experienced mRNA vaccination 2. Possible more than one index case in household 3. Index cases who experienced antiviral agent 4. Index cases who live in a nursing care facility 5. Receiving hydroxychloroquine or chloroquine in the last 60 days 6. Previous receiving passive immunization including convalescent plasma or sera, monoclonal antibodies, hyper immunoglobulin in last 60 days 7. Who do not agree to give additional information from telephone or SMS

Design outcomes

Primary

Measure	Time frame
Secondary attack rate of vaccinated and unvaccinated index case within 28 days proportion, adjusted odds ratio, relative risk reduction	—

Secondary

Measure	Time frame
Baseline characteristic of vaccinated and unvaccinated index cases day 1 Descriptive,Secondary attack rate of vaccinated and unvaccinated index cases classified with age range within 28 days proportion, adjusted odds ratio,Secondary attack rate of varaint of concerns in vaccinated and unvaccinated group within 28 days proportion, adjusted odds ratio,Secondary attack rate of vaccinated and unvacccinated index cases classified with household size within 28 days proportiopn, adjusted odds ratio,Secondary attack rate of vaccinated and unvaccinated index cases after 1st and 2nd dose vaccination within 28 days proportion, adjusted odds ratio,Secondary attack rate of vaccinated and unvaccinated index cases after complete vaccination within 90 days and more than 90 days within 28 days proportion, adjusted odds ratio,Secondary attack rate of vaccinated and unvaccinated group index cases classified with residential style within 28 days proportion,Secondary attack rate of vaccinated and unvaccinated index cases who using face mask and non-using face mask within 28 days proportion, adjusted odds ratio,Secondary attack rate of each range of cycle threshold value in vaccinated and unvaccinated index cases within 28 days proportion, adjusted odds ratio,Secondary attack rate of vaccinated and unvaccinated index cases who have vaccinated households and unvaccinated households within 28 days proportion, adjusted odds ratio, relative risk reduction,Secondary attack rate of vaccinated and unvaccinated index cases classified with severity within 28 days proportion, adjusted odds ratio,Secondary attack rate of vaccinated and unvaccinated index cases classified with duration of illness within 28 days proportion, adjusted odds ratio	—

Measure

Time frame

Baseline characteristic of vaccinated and unvaccinated index cases day 1 Descriptive,Secondary attack rate of vaccinated and unvaccinated index cases classified with age range within 28 days proportion, adjusted odds ratio,Secondary attack rate of varaint of concerns in vaccinated and unvaccinated group within 28 days proportion, adjusted odds ratio,Secondary attack rate of vaccinated and unvacccinated index cases classified with household size within 28 days proportiopn, adjusted odds ratio,Secondary attack rate of vaccinated and unvaccinated index cases after 1st and 2nd dose vaccination within 28 days proportion, adjusted odds ratio,Secondary attack rate of vaccinated and unvaccinated index cases after complete vaccination within 90 days and more than 90 days within 28 days proportion, adjusted odds ratio,Secondary attack rate of vaccinated and unvaccinated group index cases classified with residential style within 28 days proportion,Secondary attack rate of vaccinated and unvaccinated index cases who using face mask and non-using face mask within 28 days proportion, adjusted odds ratio,Secondary attack rate of each range of cycle threshold value in vaccinated and unvaccinated index cases within 28 days proportion, adjusted odds ratio,Secondary attack rate of vaccinated and unvaccinated index cases who have vaccinated households and unvaccinated households within 28 days proportion, adjusted odds ratio, relative risk reduction,Secondary attack rate of vaccinated and unvaccinated index cases classified with severity within 28 days proportion, adjusted odds ratio,Secondary attack rate of vaccinated and unvaccinated index cases classified with duration of illness within 28 days proportion, adjusted odds ratio

—

Countries

Thailand

Contacts

Public ContactTaweegrit Siripongboonsitti

Chulabhorn Hospital, Chulabhorn Royal Academy

taweegrit.sir@pccms.ac.th0816924872

Outcome results

None listed

Source: TCTR (via WHO ICTRP) · Data processed: Aug 9, 2026