Safety and immunogenicity of inactivated COVID-19 vaccine and virus vector vaccine in Thai adults with previous infection: Clinical trial

Status

Active, not recruiting

Phases

Unknown

Study type

Observational

Source

TCTR

Registry ID

TCTR20210520004

Enrollment

120

Registered

2021-05-20

Start date

2021-05-14

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

Healthy but had been previously infected with COVID-19 safety, immunogenicity, inactivated, virus vector COVID-19, vaccine

Interventions

This group received one dose of CoronaVac vaccine (if previous infection lasted shorter than 6 months) or two doses of CoronaVac vaccine (if previous infection lasted longer than 6 months).,This gro

Basic Science,Basic Science

CoronaVac,Virus vector

Eligibility

Sex/Gender

All

Age

18 Years to No maximum

Inclusion criteria

Inclusion criteria: 1. Healthy individuals above 18 years of age 2. History of COVID-19 infection confirmed by RT-PCR, with no symptoms for at least 28 days 3. Not in immunosuppresive conditions

Exclusion criteria

Exclusion criteria: 1. Having received any COVID-19 vaccinations 2. Are being treated, hospitalized or have symptoms of COVID-19

Design outcomes

Primary

Measure	Time frame
Immunogenicity 1 month post vaccination Anti-Spike RBD IgG	—

Secondary

Measure	Time frame
T cell response 1 month post vaccination IFN-gamma release after T cell stimuation	—

Countries

Thailand

Contacts

Public ContactYong Poovorawan

Chulalongkorn University

yong.p@chula.ac.th022564000

Outcome results

None listed

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