Preliminary study: Safety and Immunological Response following COVID-19 Vaccination in COVID-19 survivors

Status

Recruiting

Phases

Phase 2

Study type

Interventional

Source

TCTR

Registry ID

TCTR20210720005

Enrollment

180

Registered

2021-07-20

Start date

2021-08-10

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

COVID-19 survivors COVID-19 survivors COVID-19 Vaccination

Interventions

CoronaVac vaccination after 10+/-4 weeks COVID-19 diagnosis,ChAdOx1 vaccination after 10+/-4 weeks COVID-19 diagnosis,BNT162b2 vaccination after 10+/-4 weeks COVID-19 diagnosis,CoronaVac vaccination

Experimental Biological/Vaccine,Experimental Biological/Vaccine,Experimental Biological/Vaccine,Experimental Biological/Vaccine,Experimental Biological/Vaccine,Experimental Biological/Vaccine

Group 1,Group 2,Group 3,Group 4,Group 5,Group 6

Eligibility

Sex/Gender

All

Age

18 Years to No maximum

Inclusion criteria

Inclusion criteria: 1. Males or females at least 18 years of age (inclusive) 2. Had a history of SARS-CoV-2-positive by RT-PCR from airway specimens at screening day (10+/-4 weeks or 20+/-4 weeks after detection) 3. Can understand Thai language through speaking, reading and writing 4. Able to communicate through electronic tools such as Google form or line 5. Capable of attending all study visits according to the study schedule 6. Capable of informed consent and provision of written informed consent before any study procedures

Exclusion criteria

Exclusion criteria: 1. Have history of severe drug or vaccine allergy (anaphylaxis) 2. Have received blood transfusion, plasma, blood product, blood components, immunoglobulins, antiviral or antibodies within the last 90 days 3. Have history of cigarettes smoking, alcohol drinking and history of drug abuse 4. Be pregnant 5. Have history of any vaccination within 14 days before screening visit 6. Had received more than one COVID-19 vaccination before diagnosis of COVID-19 infection 7.Had received any COVID-19 vaccination after Yes diagnosis of COVID-19 infection 8. Have unstable disease or could not control the symptom 9.Have history of immunodeficiency or use immunosuppressant or steroid drugs? 10. Have any unusual symptoms or medical history that considered unable to participate in the study

Design outcomes

Primary

Measure	Time frame
Adverse events 4 weeks amount of adverse events	—

Secondary

Measure	Time frame
Immune response 24 weeks Immune response level	—

Countries

Thailand

Contacts

Public ContactSuvimol Niyomnaitham

Mahidol University

suvimol.niy@mahidol.ac.th0816688558

Outcome results

None listed

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