EFFECTIVENESS, SAFETY AND IMMUNOGENICITY OF THE HALF DOSE OF THE VACCINE ChadOx1 nCoV-19 (AZD1222) for COVID-19
试验速览
- 阶段
- 2 期
- 发起方
- 入组人数
- 29,637
- 试验地点
- 2
- 主要终点
- Incidence of new cases
研究概览
简要总结
This study is clinical trial (intervention study with external comparison group) to test vaccination with reduced dose (half dose) of ChAdOx1 nCoV-19 (AZD1222), in a 2-dose schedule with an interval of 8 weeks, including all adults aged 18 to 49 years from Viana city - Espírito Santo (ES)/Brazil, on the incidence of new cases over 12 months following treatment, compared to an external group from same state and adjusted for socio-demographic and epidemiological variables.
详细描述
This study is clinical trial (intervention study with external comparison group) to test vaccination with reduced dose (half dose) of ChAdOx1 nCoV-19 (AZD1222), in a 2-dose schedule with an interval of 8 weeks, including all adults aged 18 to 49 years from Viana city - Espírito Santo (ES)/Brazil, on the incidence of new cases over 12 months following treatment, compared to an external group from same state and adjusted for socio-demographic and epidemiological variables. Cellular and humoral immunity will be studied in a representative sub-sample compared to an external reference group (cohort of health workers) vaccinated with standard dose. The outcomes will be evaluated at 28 days after the second dose and follow-up after 6 months and 12 months. The main outcome will be to decrease in 60% the incidence of new cases over 6 months after receiving the vaccine. The clinical epidemiological variables will be obtained from e-SUS VS, e-SUS notifica and datasus: number of cases, number of deaths with specific ICD for covid-19, number of hospital admissions for covid-19; number of ICU admissions for the treatment of SARS, total number of tests (RT-PCR) performed and positive. The cellular and humoral immune response will be assessed by viral neutralization assay (neutralizing antibody test), serological assay by chemiluminescence, determination of specific IgM and IgG profiles, measurement of systemic soluble factors (chemokines, cytokines and growth factors), stimulation antigen-specific peripheral blood mononuclear cells in vitro and investigation of memory T and B lymphocytes and intracytoplasmic cytokines. It is estimated to include 29,637 people in the study, to reach 85% vaccination cover of individuals aged 18-49 years. The subsample size immunogenicity test is 600 individuals from the eligible population, estimating losses of 15% and study power of 90%, alpha error of 1%. The hypothesis of the study is that the reduction in the incidence of covid-19 and the cellular and humoral immune response achieved with a half dose will be similar to the reduction expected with the standard dose.
研究设计
- 研究类型
- Interventional
- 分配方式
- Non Randomized
- 干预模型
- Sequential
- 主要目的
- Prevention
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 49 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •residents of Viana, Espírito Santo, aged between 18 and 49 years
排除标准
- •Pregnant women;
- •History of severe allergic reaction (anaphylaxis) to any previously administered vaccine;
- •Having received another vaccine in the last 14 days;
- •Belonging to a priority risk group for vaccination, as per the PNI recommendations;
- •Have fever or flu-like symptoms;
- •Have previously received any vaccine for covid-19 at any time;
- •Recent diagnosis of covid-19 with onset of symptoms 28 days before vaccination;
- •Disorders of coagulation and use of anticoagulants.
结局指标
主要结局
Incidence of new cases
时间窗: 12 months
Incidence of new cases over 12 months following treatment
次要结局
- Viral Neutralization Assay(4 and 8 months)
- serological assay(8 and 10 months)
- Antigen-specific stimulation of peripheral blood mononuclear cells(10 and 12 months)
- Lymphocyte investigation(10 and 12 months)
- Number of deaths(12 months)
- number of intensive care unit (ICU) admissions(12 months)
- number of tests (RT-PCR)(12 months)
- IgM(8 and 10 months)
- number of hospital admissions(12 months)
- IgG(8 and 10 months)
- systemic soluble factors(8 and 10 months)
- Cytokine investigation(10 and 12 months)
研究者
Valéria Valim
Professor
Federal University of Espirito Santo