A Randomized, Observer-blind Trial to Assess the Immunogenicity and Safety of Third Dose Vaccination With AstraZeneca COVID-19 Vaccine or Pfizer/BioNTech COVID-19 Vaccine Among Thai Adults Receiving Two Doses of Sinovac
试验速览
- 阶段
- 2 期
- 状态
- 已完成
- 入组人数
- 1,250
- 试验地点
- 14
- 主要终点
- GMT Anti-S IgG at baseline and after vaccination
研究概览
简要总结
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)
详细描述
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.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Prevention
- 盲法
- Double (Participant, Investigator)
盲法说明
Unblinded study staff will be responsible for preparing study products (in accordance with the randomly determined assignment), administering the study vaccine, and handling all drug accountability procedures. These personnel will not participate in the other aspects of the clinical trial, to help ensure the integrity of the blind at the site. Unblinded staff will retrieve a participant's randomization assignment after being informed by the PI or designee that a participant is eligible for randomization. They will prepare study vaccine (AZ or PF) with dose (full or half dose) based on the participant's randomization
入排标准
- 年龄范围
- 20 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Adult male or female age equal or more than 20 years with Thai ID cards
- •Received two doses (21-28 days apart) of Sinovac inactivated COVID-19 vaccine who will be divided according to their intervals 60-less than 90 days, 90-less than120 days and 120-180 days
- •Has provided written informed consent prior to performance of any study-specific procedure
- •No history of fever or PUI symptoms within 7 days
排除标准
- •Any confirmed or suspected immunosuppressive or immunodeficient state.
- •Contraindication to AZ or PF according to labelling of the products
- •History of COVID infection within 3 months period
结局指标
主要结局
GMT Anti-S IgG at baseline and after vaccination
时间窗: Day 0, Day 28, Day 60 and Day 90
GMT Anti-S IgG at baseline and after vaccination at day 28, day 60 and day 90
GMFR changed from baseline in anti-S IgG GMT after vaccination
时间窗: Day 28, Day 60 and Day 90
GMFR changed from baseline in anti-S IgG GMT at 28,60 and 90 days after vaccination
Anti-S IgG Seroresponses changed from baseline after vaccination
时间窗: Day 28, Day 60 and Day 90
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
GMFR changed from baseline in NT50 against SARS-CoV-2 pseudovirus after vaccination
时间窗: Day 28 and Day 90
GMFR changed from baseline in NT50 against SARS-CoV-2 pseudovirus at 28 and 90 days vaccination
Frequency of solicited reportable local adverse event after vaccination
时间窗: Day 0 through Day 7
Frequency and percentage of solicited reportable local adverse events (pain or tenderness, erythema, swelling or induration) of vaccination
Frequency of solicited reportable systemic adverse event after vaccination
时间窗: Day 0 through Day 7
Frequency and percentage of solicited reportable systemic adverse events (fever, headache, fatigue or malaise, myalgia, arthralgia, nausea or vomitting) of vaccination
Frequency of all unsolicited AEs
时间窗: Day 0 through Day 28
Frequency and percentage of all unsolicited AEs
Frequency of SAEs
时间窗: Day 0 through Day 90
Frequency and percentage of SAEs throughout the entire study period
GMT against SARS-Cov-2 pseudovirus (PVNT) Neutralizing antibody titer 50 at baseline and after vaccination
时间窗: Day 0, Day 28 and Day 90
GMT against SARS-Cov-2 pseudovirus (PVNT) Neutralizing antibody titer 50 at baseline and after vaccination at day 28 and day 90
次要结局
- 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(Day 28 and Day 90)
- NT50 GMT against SARS-Cov-2 by micro neutralization assay at baseline and day 28 and day 90 after vaccination(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(Day 28 and Day 90)