Clinical Trials Logo

Clinical Trial Summary

This prospective, multi-center, randomized, observer-blind Phase 2 study. A total of 1320 participants will be divided into 2 groups (660 each) receiving either full dose or half dose of either AZ or PF. Each group is further stratified into 3 subgroups according to three interval duration in term of days after second dose of SV for 60 to less than 90 days, 90 to less than120 days and 120 to 180 days. Each group will be randomized to receive either AZ or PF in 1:1 ratio. Subjects who fulfilled eligibility criteria will be randomly assigned to receive either full dose or half dose of AZ or PF in 1:1 ratio as an IM injection in the deltoid muscle at Visit 1 (V1). Subjects will be follow-up for assessing immunity at day 28 (V3), day 60 (V4) and day 90 (V5) and for safety at day 7 (V2), day 28 (V3), day 60 (V4) and day 90 (V5). At least 50% from each subgroup will be randomly selected to provide additional blood at baseline (V1, day 0) and day 28 (V3) to be used for assessment of T-cell-mediated immunity (CMI)


Clinical Trial Description

This study has been designed to assess immune response and safety of third dose vaccination with AstraZeneca ChAdOx1AZD1222 vaccine or Pfizer/BioNTech BNT162b2 vaccine among Thai subjects who have received two doses of Sinovac. The types of vaccines provided by the government included 7.7 million doses of inactivated vaccine manufactured by Sinovac and 6.5 million doses of AstraZeneca ChAdOx1 AZD1222 vaccine. With the limited supplies of COVID vaccines in many regions of the world especially in LMIC including Thailand and the evidences of waning immunity of especially inactivated vaccine have raised the concerns whether third dose is needed. The third dose that available now in Thailand are AstraZeneca ChAdOx1AZD1222 vaccine (AZ)/ Pfizer/BioNTech BNT162b2 vaccine (PF) and whether this can be provided with half dose so that the vaccination coverage is going to be higher in spite of limited vaccine supplies. A number of studies have proved that COVID-19 vaccines are effective at preventing people from getting severe COVID-19 disease. However, the vaccines do not only reduce the chance of infection, but they also help to mitigate disease severity. Study population: Male and female adults aged equal or more than 20 years who received two doses of Inactivated COVID-19 vaccine developed by Sinovac (given at 21-28 days apart) at different intervals of 60 to less than 90 days, 90 to less than120 days and 120 to 180 days This prospective, multi-center, randomized, observer-blind Phase 2 study, A total of 1320 participants will be divided into 2 groups (660 each) receiving either full dose or half dose of either AZ or PF. Each group is further stratified into 3 subgroups according to three interval duration in term of days after second dose of SV for 60-less than 90 days, 90-less than120 days and 120-180 days respectively. Subjects who fulfilled eligibility criteria will be randomly assigned to receive either full dose or half dose of AZ or PF in 1:1 ratio as an IM injection in the deltoid muscle at Visit 1 (V1). All participants will be randomized based on dose given either full dose or half dose and further stratify accordingly by Interactive web-based response system (IWRS). There will be unblinded team which consists of pharmacist and nurse who will give injection. All the safety assessment will be performed independently by clinical team. Subjects will be follow-up for assessing immunity at day 28 (V3), day 60 (V4) and day 90 (V5) and for safety at day 7 (V2), day 28 (V3), day 60 (V4) and day 90 (V5). ;


Study Design


Related Conditions & MeSH terms


NCT number NCT05049226
Study type Interventional
Source Mahidol University
Contact
Status Completed
Phase Phase 2
Start date September 24, 2021
Completion date February 22, 2022

See also
  Status Clinical Trial Phase
Active, not recruiting NCT04997551 - Double Blind Randomized Clinical Trial of Use of Colchicine Added to Standard Treatment in Hospitalized With Covid-19 Phase 3
Recruiting NCT04977024 - SARS-CoV-2 Vaccine (GEO-CM04S1) Versus mRNA SARS-COV-2 Vaccine in Patients With Blood Cancer Phase 2
Terminated NCT04455815 - A Trial Looking at the Use of Camostat in People Who Have Tested Positive for Coronavirus (COVID-19) (SPIKE-1) Phase 2
Completed NCT04666025 - SARS-CoV-2 Donor-Recipient Immunity Transfer
Completed NCT04662437 - The Status of Parathyroid Hormone Secretion in Covid-19 Patients
Recruiting NCT05792878 - Study of COVID-19 Infection and Its Clinical Prognosis in Chronic Hepatitis B Patients With Antiviral Therapy
Completed NCT04659200 - Thyroid Function Tests and Status of Thyroid Autoantibodies in Covid-19 Patients
Recruiting NCT04470583 - Evaluating Clinical Parameters of COVID-19 in Pregnancy
Withdrawn NCT04377568 - Efficacy of Human Coronavirus-immune Convalescent Plasma for the Treatment of COVID-19 Disease in Hospitalized Children Phase 2
Completed NCT04848610 - The Factors That Affect the Infection of COVID-19
Recruiting NCT04582903 - Send-In Sample Collection for Comprehensive Analyses of Innate and Adaptive Immune Responses During Acute COVID-19 and Convalescence
Recruiting NCT06032000 - Evaluation of Safety and Immunogenicity of a SARS-CoV-2(Severe Acute Respiratory Syndrome Coronavirus 2) Booster Vaccine (LEM-mR203) Phase 1
Terminated NCT04941703 - "CHANGE COVID-19 Severity" Phase 1/Phase 2
Active, not recruiting NCT04639466 - A Synthetic MVA-based SARS-CoV-2 Vaccine, GEO-CM04S1, for the Prevention of COVID-19 Infection Phase 1/Phase 2
Completed NCT04575038 - CRISIS2: A Phase 2 Study of the Safety and Antiviral Activity of Brequinar in Non-hospitalized Pts With COVID-19 Phase 2
Recruiting NCT05022446 - The Impact of COVID-19 on Pulmonary Procedures
Completed NCT04347798 - IMPACT: IMPact of Antimalarials on Covid-19 Infections in RAPPORT
Active, not recruiting NCT04650178 - Well-being in Cancer Patients With Neuropathy During COVID-19 Who Participated in Prior Clinical Trials
Recruiting NCT04169542 - Impact of COVID-19 Pandemic on Out-of-Pocket Costs, Lost Wages, and Unemployment in Patients With Breast Cancer Undergoing Breast Surgery
Recruiting NCT04382781 - Immunosupressive Treatment in COVID-19 Patients