Antibody responses to mRNA COVID-19 vaccine (BNT162b2) in Thai children aged 5-11 years who were previously infected with SARS-CoV-2.

Status

Active, not recruiting

Phases

Phase 4

Study type

Interventional

Source

TCTR

Registry ID

TCTR20230123005

Enrollment

200

Registered

2023-01-23

Start date

2022-03-06

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 Thai children aged 5-11 years who were previously infected with SARS-CoV-2 children, previous infection, SARS-CoV-2, COVID-19, vaccines, mRNA vaccines, Adverse events, Vaccine safety

Interventions

COVID-19 mRNA vaccine (Comirnaty) orange Cap 10 microgram/dose (Standard dose), administered intramuscularly 2 doses 10 weeks (+/-2 weeks) apart,COVID-19 mRNA vaccine (Comirnaty) orange Cap 5 microgr

Active Comparator Biological/Vaccine,Experimental Biological/Vaccine

COVID-19 mRNA vaccine (Comirnaty) orange Cap,COVID-19 mRNA vaccine (Comirnaty) orange Cap

Eligibility

Sex/Gender

All

Age

5 Years to 11 Years

Inclusion criteria

Inclusion criteria: 1. The subject is aged 5 to less than 12 years. 2. Previously infected with SARS-CoV-2 (confirmed by PCR or ATK test result) at least one month from onset or had positive result 3. Have not received any covid vaccines 4. Can understand Thai language through speaking, reading, and writing 5. Capable of attending all study visits according to the study schedule

Exclusion criteria

Exclusion criteria: 1. Have any history of severe drug or vaccine allergy (anaphylaxis) 2. Have received any other vaccines within 14 days for live vaccines or 28 days for inactivated vaccines (excepted influenza vaccine) 3. Have body temperature more than equal 38 C or 100.4 F within 24 hours prior received study vaccine 4. Have received blood transfusion, plasma, blood product, blood components, immunoglobulins, antiviral, or antibodies within the last 90 days 5. Have any history of immunodeficiency or received immunosuppressants or received steroids drugs 6. Have any conditions that are considered unsuitable for clinical study by the investigator

Design outcomes

Primary

Measure	Time frame
Anti-spike RBD antibody 2-4 weeks after vaccination Chemiluminescent microparticle immunoassay (CMIA) ,Cell-mediated immune responses 2-4 weeks after vaccination ELISpot assays, Neutralizing antibody 2-4 weeks after vaccination Neutralizing Antibody Assays	—

Secondary

Measure	Time frame
Adverse event 7 days after vaccination Observe local and systemic reactions.	—

Countries

Thailand

Contacts

Public ContactWanatpreeya Phongsamart

Siriraj Hospital Mahidol University

wanatpreeya@gmail.com028660225

Outcome results

None listed

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