A Phase 2 interventional study of AstraZeneca ChAdOx1 AZD1222 vaccine (AZ) full dose and Pfizer/BioNTech BNT162b2 vaccine (PF) full dose in COVID-19 Infection and COVID-19 VACCINE, sponsored by Mahidol University. Completed at 7 sites in Thailand. Open to participants aged 20 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2022-07-06.
Sponsored by Mahidol University · Phase 2, Interventional, and Prevention
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)
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).
6,687 studies on the registry are indexed under Infections; 807 are open to participants now.
This study's enrollment of 1,250 is above the median of 120 across 4,200 interventional studies indexed under Infections.
Browse Infections studies →Mahidol University is the lead sponsor of 730 studies on the registry; 118 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
Participants who have received two doses of SV at interval 60 to less than 90 days
Biological: AstraZeneca ChAdOx1 AZD1222 vaccine (AZ) full dose · Biological: Pfizer/BioNTech BNT162b2 vaccine (PF) full dose · Biological: AstraZeneca ChAdOx1 AZD1222 vaccine (AZ) half dose · Biological: Pfizer/BioNTech BNT162b2 vaccine (PF) half dose
Participants who have received two doses of SV at interval 90 to less than 120 days
Biological: AstraZeneca ChAdOx1 AZD1222 vaccine (AZ) full dose · Biological: Pfizer/BioNTech BNT162b2 vaccine (PF) full dose · Biological: AstraZeneca ChAdOx1 AZD1222 vaccine (AZ) half dose · Biological: Pfizer/BioNTech BNT162b2 vaccine (PF) half dose
Participants who have received two doses of SV at interval 120 to 180 days
Biological: AstraZeneca ChAdOx1 AZD1222 vaccine (AZ) full dose · Biological: Pfizer/BioNTech BNT162b2 vaccine (PF) full dose · Biological: AstraZeneca ChAdOx1 AZD1222 vaccine (AZ) half dose · Biological: Pfizer/BioNTech BNT162b2 vaccine (PF) half dose
Astrazeneca COVID-19 (ChAdOx1 AZD1222) vaccine: One dose (0.5 ml) contains: COVID-19 Vaccine (ChAdOx1-S\* recombinant) 5 × 10\^10 viral particles (vp) \*Recombinant, replication-deficient chimpanzee adenovirus vector encoding the SARS-CoV-2 Spike glycoprotein. Produced in genetically modified human embryonic kidney (HEK) 293 cells. Administer: Intramuscular (IM) injection in the deltoid muscle
Pfizer-BioNTech COVID-19 (BNT162b2) vaccine: Diluent: 0.9% sodium chloride (normal saline, preservative-free) Administer: Intramuscular (IM) injection in the deltoid muscle
Astrazeneca COVID-19 (ChAdOx1 AZD1222) vaccine: One dose (0.5 ml) contains: COVID-19 Vaccine (ChAdOx1-S\* recombinant) 5 × 10\^10 viral particles (vp) \*Recombinant, replication-deficient chimpanzee adenovirus vector encoding the SARS-CoV-2 Spike glycoprotein. Produced in genetically modified human embryonic kidney (HEK) 293 cells. Administer: Intramuscular (IM) injection in the deltoid muscle
Pfizer-BioNTech COVID-19 (BNT162b2) vaccine: Diluent: 0.9% sodium chloride (normal saline, preservative-free) Administer: Intramuscular (IM) injection in the deltoid muscle
GMT Anti-S IgG at baseline and after vaccination
GMT Anti-S IgG at baseline and after vaccination at day 28, day 60 and day 90
Time frame: Day 0, Day 28, Day 60 and Day 90
GMFR changed from baseline in anti-S IgG GMT after vaccination
GMFR changed from baseline in anti-S IgG GMT at 28,60 and 90 days after vaccination
Time frame: Day 28, Day 60 and Day 90
Anti-S IgG Seroresponses changed from baseline after vaccination
Frequency and percentage of participants with seroresponses in anti-S IgG titer as defined by (1) a ≥ 4-fold increase from baseline at 28, 60 and 90 days after vaccination (2) a ≥ 10-fold increase from baseline at 28,60 and 90 days after vaccination
Time frame: Day 28, Day 60 and Day 90
GMT against SARS-Cov-2 pseudovirus (PVNT) Neutralizing antibody titer 50 at baseline and after vaccination
GMT against SARS-Cov-2 pseudovirus (PVNT) Neutralizing antibody titer 50 at baseline and after vaccination at day 28 and day 90
Time frame: Day 0, Day 28 and Day 90
GMFR changed from baseline in NT50 against SARS-CoV-2 pseudovirus after vaccination
GMFR changed from baseline in NT50 against SARS-CoV-2 pseudovirus at 28 and 90 days vaccination
Time frame: Day 28 and Day 90
Frequency of solicited reportable local adverse event after vaccination
Frequency and percentage of solicited reportable local adverse events (pain or tenderness, erythema, swelling or induration) of vaccination
Time frame: Day 0 through Day 7
Frequency of solicited reportable systemic adverse event after vaccination
Frequency and percentage of solicited reportable systemic adverse events (fever, headache, fatigue or malaise, myalgia, arthralgia, nausea or vomitting) of vaccination
Time frame: Day 0 through Day 7
Frequency of all unsolicited AEs
Frequency and percentage of all unsolicited AEs
Time frame: Day 0 through Day 28
Frequency of SAEs
Frequency and percentage of SAEs throughout the entire study period
Time frame: Day 0 through Day 90
NT50 GMT against SARS-Cov-2 by micro neutralization assay at baseline and day 28 and day 90 after vaccination
NT50 GMT against SARS-Cov-2 by micro neutralization assay at baseline and day 28 and 90 after vaccination
Time frame: Day 0, Day 28 and Day 90
GMFR changed from baseline in NT50 against SARS-CoV-2 (micro NT Delta/WT NA) at 28 and 90 days after vaccination among those positives by PNT assay
GMFR changed from baseline in NT50 against SARS-CoV-2 (micro NT Delta/WT NA) at 28 and 90 days after vaccination among those positives by PNT assay
Time frame: Day 28 and Day 90
NT50 seroresponses against SARS-CoV-2 using micro NT changed from baseline at 28 and 90 days after vaccination among those positive by PVNT assay
Frequency and percentage of participants with NT50 seroresponses against SARS-CoV-2 using micro NT as defined by (1) a ≥ 4-fold increase from baseline at 28 and 90 days after vaccination compare to baseline among those positive by PVNT assay
Time frame: Day 28 and Day 90
S protein-specific T cells response at baseline, 28 days after vaccination given at different intervals
Frequency and percentage of S protein-specific T cells response elicited by each of the regimens as measured by QuantiFERON at baseline and 28 days after vaccination
Time frame: Day 28
Seroresponse against SARS-CoV-2 pseudovirus towards Omicron strains at baseline, 28 and 90 days after vaccination
Frequency and percentage of subjects with % inhibition response at 1:80 dilution against SARS-CoV-2 pseudovirus as defined by more than 50% and 68% inhibition towards Omicron strains
Time frame: Day 0, 28 and 90
NT50 GMT against SARS-Cov-2 pseudovirus (pVNT) Omicrron strain at baseline 28 and 90 days after vaccination
NT50 GMT against SARS-Cov-2 pseudovirus (pVNT) Omicrron strain at baseline 28 and 90 days after vaccination
Time frame: Day 0, 28 and 90
GMFR changed from baseline in NT50 against SARS-CoV-2 pseudovirus (pVNT), Omicron strain at 28 and 90 days after vaccination
GMFR changed from baseline in NT50 against SARS-CoV-2 pseudovirus (pVNT), Omicron strain at 28 and 90 days after vaccination
Time frame: Day 28, 90
Plan to share: Yes — data or left over specimen will be shared for future study ONLY subject who consent allow using their data/specimens. Sharing will be done without personnel identification
Supporting information: Study protocol
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This study is completed, as verified in Jul 2022. You cannot join it, but the record below documents what was studied.
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