Evaluation of the Protective Efficacy of a Vaccine Derived From the Synthetic CS Protein of Plasmodium Vivax
试验速览
- 阶段
- 2 期
- 状态
- 已完成
- 入组人数
- 32
- 试验地点
- 1
- 主要终点
- Protective efficacy against P. vivax infection on volunteers exposed to infected mosquito bites
研究概览
简要总结
This is a randomized, double-blind, controlled, which seeks to compare two groups of volunteers (naive and previously exposed to malaria) who were made 3 immunizations with a synthetic derivative of the CS protein of Plasmodium vivax in order to determine their protective efficacy. Then volunteers will be subject to an infectious challenge to assess the infectivity of gametocytes in the blood early stage of P. vivax in Anopheles albimanus mosquitoes.
详细描述
This study is a prospective controlled, blinded clinical trial, designed to establish the protective efficacy induced by the vaccine PvCSP between human volunteers with and without history of malaria.
Study subjects
This study will require the involvement of two types of volunteers:
- Parasite donors: 5-15 P. vivax-infected patients who will serve as parasites donors for experimental infection of mosquitoes, who will be enrolled in the endemic area.
- Volunteers for immunization: Two other groups of volunteers will be immunized with the vaccine PvCSP. A group of 16 people without previous exposure to malaria (naive) and another 16 people with a history of previous malaria infection (pre-immune).
Methodology Recruitment of infected patients: Parasite donors will be recruited among P. vivax infected patients attending a diagnostic center in the endemic area.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Basic Science
- 盲法
- Triple (Participant, Care Provider, Investigator)
入排标准
- 年龄范围
- 18 Years 至 45 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Naïve group
- •Healthy men and women aged 18-45 years. Signing freely and voluntary informed consent , accompanied by two witnesses who also sign.
- •Not have a history of malaria infection. For women, use of adequate contraception from the star restriction to be lifted by a doctor for contraception study. Accept not to travel to areas considered endemic for malaria during Trophies infectious period (1 month ) ( Buenaventura , Tierralta , Pretoria , Tumaco ,Urabá and Bajo Cauca) .
- •Be reachable by phone throughout the study period. Being Duffy positive ( Fy +) . Levels of hemoglobin ( Hb) > 11 g / dl. Availability to participate during the period in which they develop the study. Do not be participating in another clinical study
- •Preimmune group
- •Healthy men and women aged 18-45 years. Signing freely and voluntary informed consent , accompanied by two witnesses who also sign .
- •Having a history of infection (s ) and serological tests for malaria positive for P. vivax.
- •For women, use adequate contraception from the start restriction to be lifted by a doctor for contraception study .
- •Accept not to travel to areas considered endemic for malaria during Trophies infectious period (1 month ) ( Buenaventura , Tierralta , Pretoria , Tumaco Urabá and Bajo Cauca) .
- •Be reachable by phone throughout the study period. Availability to participate during the period in which they develop the study.
- •Voluntary blood donors
- •Healthy men and women aged 18-45 years.
- •Be positive diagnosis of P. vivax determined by thick smear examination .
- •The patient must not have circulating malaria parasites such as P. falciparum or P. malariae .
- •Have a parasitemia ≥ 0.1 %. by thick smear .
- •Hb ≥ 9 g / dL at the time of diagnosis of malaria.
- •The patient must have the capacity to provide informed consent freely and voluntarily . Should be illiterate may assert its decision to participate by putting their fingerprint in the format consent. Minors who are between 15 and 17 and wishing to participate must sign the informed consent and one of its Parents must sign the informed consent, accompanied by 2 witnesses who also sign
排除标准
- •Negative IFAT (< 1:20) for P. vivax on screening tests
- •Other criteria used in the case of naive volunteers, except a history of having lived in an endemic area for the past 6 months.
- •Step 2 Patients that have chronic or acute disease, different from malaria by P. vivax.
- •Having a history of disease or clinical conditions that according to medical criteria might increase significantly the risk related with participation on this study Hemoglobin levels <9 g/dL at the time of recruitment Have received antimalarial treatment before the diagnosis
研究组 & 干预措施
Experimental
10 individuals per sub- group to be immunized with the Vaccine PvCS N+C at month 0 and the Vaccine PvCS N+C+R at months 2 and 6
干预措施: Vaccine PvCS N+C+R (Biological)
Experimental
10 individuals per sub- group to be immunized with the Vaccine PvCS N+C at month 0 and the Vaccine PvCS N+C+R at months 2 and 6
干预措施: Vaccine PvCS N+C (Biological)
Control
six individuals for each sub- group to be immunized with placebo SSN Montanide ISA-51
干预措施: SSN Montanide ISA-51 (Biological)
结局指标
主要结局
Protective efficacy against P. vivax infection on volunteers exposed to infected mosquito bites
时间窗: Thirty days after the last immunization
Vaccine protective efficacy against P. vivax infection on volunteers exposed to infected mosquito bites
次要结局
- Antibody functionality in vitro through inhibition of sporozoite invasion (ISI) to Hep-G2 cells.(Every 2 months)
- Changes on vaccine biological security(On the day next to immunization and 1 or 2 weeks before the next immunization)
- Evolution of antibody titers(At months 0, 2, 4 and 6 of the trial)
- Specific cytokine induction(At months 0, 2, 4 and 6 of the trial)
- Vaccine-induced protection for P. vivax(28 days after mosquito bites)
研究者
Socrates Herrera Valencia
MD
Malaria Vaccine and Drug Development Center