Randomized Controlled Trial to Assess the Immunogenicity and Safety of Full Versus Fractional Dose of Pfizer/BioNTech, AstraZeneca, and Sinovac COVID-19 Vaccines Given as a Booster Dose at Least 6 Months After Primary Vaccination Series or PCR-confirmed Infection With SARS-CoV-2 in Healthy Adults
试验速览
- 阶段
- 4 期
- 状态
- 已完成
- 发起方
- 入组人数
- 2,354
- 试验地点
- 2
- 主要终点
- Sero-response rate by Spike IgG binding ELISA at 28 days post booster
研究概览
简要总结
Since the emergence of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pathogen in late 2019, millions of people around the world have fallen ill and died from coronavirus disease 2019 (COVID-19), with variant-fueled case spikes causing repeated cycles of morbidity and mortality. The rapid development and emergency use authorization of vaccines against SARS-CoV-2 presents an enormous opportunity to protect populations, but bottlenecks in production have led to demand for vaccines that far outpaces supply. This project will investigate the immunogenicity of fractional doses of SARS-CoV-2 vaccines given a minimum of six months following an initial two-dose schedule or following natural immunity via documented infection. The consortium of research partners from the Sabin Vaccine Institute, Aga Khan University, Fundação Oswaldo Cruz (Fiocruz), and Stanford University will recruit volunteers to receive a full or fractional booster dose of BNT162b2, AZD1222 or Sinovac following receipt of their primary vaccination series or PCR-confirmed natural infection in Pakistan. The research team will follow participants for six months from boosting, with blood draws at baseline, 28 days, 3 months and 6 months, and measure sero-response rate (SRR) by anti-Spike immunoglobulin G (IgG) binding enzyme-linked immunosorbent assay (ELISA) with the ultimate aim of identifying whether fractional doses provide a similar immune response compared to full doses of vaccine.
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
- Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
盲法说明
The study will be observer-blind. Participants, data collectors (e.g., Investigator), and data evaluators (e.g., trial statisticians) are blinded. Only the staff involved in vaccine delivery will be unblinded and aware of which vaccine the participant is receiving (group allocation). Study staff who collect information on symptoms and adverse events, laboratory staff and statisticians conducting the analysis will all be blinded to the vaccine and dosage received.
入排标准
- 年龄范围
- 18 Years 至 60 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Healthy male or female individuals aged 18 years to 60 years
- •Participant is willing and able to give written informed consent for participation in the trial
- •Individuals who can comply with trial procedures and are available for the duration of follow-up.
- •● Previous vaccination with a complete primary series of Sinovac (Priming Group 1), AZD1222 (Priming Group 2), or BNT162b2 (Priming Group 3-B) at least 6 months prior to screening
- •● Previous vaccination with a complete primary series of Sinovac (Priming Group 1) or AZD1222 (Priming Group 2) at least 6 months prior to screening, or PCR-confirmed natural infection (Priming Group 3-P) between February 2021 - 6 months prior to screening
排除标准
- •Has a contraindication to BNT162b2, AZD1222 or Sinovac
- •Has received an incomplete primary COVID-19 vaccination series
- •Has received 3 doses of COVID-19 vaccine
- •Has received heterologous primary COVID-19 vaccination series
- •History of a solid organ or bone marrow transplant
- •History of malignancy (other than non-melanoma skin cancer) within the past five years
- •Currently on hemodialysis
- •Any confirmed or suspected immunosuppressive or immunodeficiency condition or diagnosis
- •On chronic (>30 days) use of immunosuppressive medications at the time of enrollment (except topical steroids or short-term oral steroids, i.e., ≤14 days)
- •Known diagnosis of HIV with CD4 count <200 cells/mm3 (in the past 6 months)
- •Active or history of previous auto-immune neurological disorders (e.g., multiple sclerosis, Guillain-Barre syndrome, transverse myelitis) (excluding Bell's palsy)
- •Has received anti-CD20 monoclonal antibodies for any reason in the past 12 months
- •Has received monoclonal antibodies to treat a previous COVID-19 event
- •Pregnant at screening
- •Positive SARS-CoV-2 Antigen test in respiratory specimen at screening
- •Planning to migrate out of the study area within 6 months of the enrollment
- •Participants currently enrolled in any other COVID-19 vaccine research trial in which they are getting a COVID-19 vaccine during the study period
- •Illiterate individuals (Brazil only)
- •Has a severe and/or uncontrolled comorbidity
- •Pakistan (natural infection Priming Group (Priming Group 3-P)):
- •● Prior vaccination with ANY vaccine against COVID-19
结局指标
主要结局
Sero-response rate by Spike IgG binding ELISA at 28 days post booster
时间窗: Day 28
Assess and compare humoral immune response from a fractional vs. full booster dose of BNT162b2 or AZD1222 in immunocompetent adults fully primed with BNT162b2, AZD1222, or Sinovac vaccines or natural infection, measured by anti-Spike IgG binding ELISA at 28 days post booster
Safety and reactogenicity profile of fractional and full dose of study vaccines at 28 days post-booster vaccination
时间窗: Day 28
Describe the safety and reactogenicity profile of fractional and full dose of study vaccines at 28 days post-booster vaccination through estimated incidence of solicited local and systemic adverse events, and incidence of unsolicited reported adverse events 1. Occurrence of solicited local and systemic reactions within 7 days of booster 2. Occurrence of unsolicited AEs within 28 days of booster
次要结局
- Sero-response rate by anti-Spike IgG binding ELISA at 3m and 6m post booster(Month 3 and Month 6)
- Safety and reactogenicity profile of fractional and full dose of study vaccines throughout the trial(Throughout study, 6 months per participant)