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Immunogenicity and safety of the third dose COVID-19 vaccine in Thai population.

Immunogenicity and safety of the third dose COVID-19 vaccine in Thai population.

Status
Recruiting
Phases
Phase 2
Study type
Interventional
Source
TCTR
Registry ID
TCTR20210731004
Enrollment
5520
Registered
2021-07-31
Start date
2021-08-05
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

After the third dose of the COVID-19 vaccine, the immune response in healthy volunteers who received 2 doses of COVID19 vaccine (CoronaVac or ChAdOx1) at least three months. COVID-19 vaccine, Third dose, ChAdOx1, coronavac, Sinovac, BNT162b2, Sinopharm

Interventions

Administration of 0.5 ml of BBIBP-CorV intramuscular for 1 dose,Administration of 0.5 ml of AZD1222 intramuscular for 1 dose,Administration of 0.5 ml of BNT162b2 intramuscular for 1 dose,Administratio
CoronaVac/BBIBP-CorV,CoronaVac/AZD1222,CoronaVac/BNT162b2,AZD1222/BBIBP-CorV,AZD1222/BNT162b2,AZD1222/AZD1222

Sponsors

Chulabhorn Royal Academy
Lead Sponsor

Eligibility

Sex/Gender
All
Age
18 Years to No maximum

Inclusion criteria

Inclusion criteria: 1. 18 years old or more 2. No history of a severe allergic reaction to the prior vaccine. 3. No fever nor history of fever within 14 days. 4. No symptoms of respiratory tract infection within 14 days. 5. Received two doses of COVID-19 vaccine for at least 3 months 6. sign informed consent to the study.

Exclusion criteria

Exclusion criteria: 1. pregnancy. 2. lactation. 3. History of SARS-CoV-2 infection

Design outcomes

Primary

MeasureTime frame
Humoral immunity 4 weeks after third dose 4 weeks after the third dose of the vaccine Double antigen technique for detection of Antibody level of total antibody of spike protein of SARS-CoV-2

Secondary

MeasureTime frame
Safety profile after vaccination in each intervention arms 4 weeks after the third dose of the vaccine Solicited and non-solicited adverse events,Humoral immunity 4 weeks after third dose 4 weeks after the third dose of the vaccine Surrogate Neutralizing antibody

Countries

Thailand

Contacts

Public ContactKriangkrai Tawinprai

HRH Princess Chulabhorn College of Medical Science

Kriangkrai.taw@pccms.ac.th0815748167

Outcome results

None listed

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