The Impact of Vaccination With a Serogroup A Meningococcal Conjugate Vaccine on Carriage of Serogroup A Meningococci in Mali and Niger
试验速览
- 阶段
- 4 期
- 状态
- 已完成
- 入组人数
- 33,000
- 试验地点
- 3
- 主要终点
- Meningococcal carriage
研究概览
简要总结
Meningococcal disease occurs throughout the world but attack rates in the Sahelian and sub-Sahelian regions of Africa - the African meningitis belt - are many times higher than those seen in any other part of the world. During 2009, over 70,000 meningitis cases and 3,200 deaths were reported in Nigeria, Niger, and Chad alone.
In 2001, a public private partnership between WHO and PATH was created, the Meningitis Vaccine Project (MVP). The MVP set out to develop an affordable meningococcal serogroup A conjugate vaccine (MenAfriVac™) for use in the African meningitis belt. This was successfully achieved, and the new vaccine, produced by the Serum Institute of India (SII), was granted a licence in 2009 for international export. The vaccine dossier was submitted to WHO for prequalification at the beginning of 2010. Introduction through mass vaccination is planned in three African Meningitis belt countries in 2010 (Burkina Faso, Mali and Niger). The implementation of MenAfriVac will be the responsibility of the local Ministry of Health, with the support of the World Health Organization.
It is anticipated that this vaccine will be deployed in other countries of the meningitis belt in 2011. This vaccine should provide high levels of direct protection to immunised individuals but, as for serogroup C conjugate vaccines in the United Kingdom, a greater public health impact will be achieved if carriage and transmission of the infection are also prevented.
The London School of Hygiene & Tropical Medicine (LSTHM) is coordinating the African Meningococcal Carriage Consortium (MenAfriCar). One of the primary objectives of the MenAfriCar project is to evaluate the impact of the new conjugate vaccine on meningococcal carriage and transmission of serogroup A meningococci in Mali, Niger and Chad. A community-based prospective, pre- and post intervention, observational study will be conducted. MenAfriCar will also help to develop research capacity in the participating African countries.
详细描述
Epidemiological information will be obtained at community, household and individual levels.
In each country, informed consent will be obtained from adults selected to participate in the study and for the children under their care. Written informed assent will also be obtained from participants aged 12 to 15 years. Oral assent will be obtained from younger children. Once consent or assent has been obtained, a structured questionnaire will be completed following discussions with the head of the household which records information about sleeping and cooking arrangements in the household. Each study participant or their guardian will complete a questionnaire which collects information on potential risk factors for meningococcal carriage such as occupation, smoking, recent travel, including travel on the pilgrimage, attendance at social gatherings, and recent respiratory infection. Following interview, a pharyngeal swab will be obtained from each study participant. A 5 ml blood sample will be obtained from 200 randomly selected subjects in each of the four older age categories and from 50 infants aged 6 - 11 months (a total of 850 samples) during the initial survey to measure serogroup A bactericidal and Immunoglobulin G ELISA serogroup A, C, W135, X and Y meningococcal antibodies. Blood will not be collected from infants under the age of 6 months.
In each country, immediate processing of pharyngeal swabs will allow the identification of subjects who are carrying meningococci and the serogroup of these meningococci will be determined within 2 - 4 days of collection of the sample. The households of these subjects will be visited as soon as possible after identification of a carrier has been made, informed consent will be obtained and if the participant agrees, a pharyngeal swab will be obtained twice a month for two months and monthly for a further four months, a total of 8 follow-up samples to estimate the rates of acquisition and loss of carriage in household's contacts. During the first visit, a 5 ml blood sample will be obtained from all subjects over the age of 6 months for measurement of IgG ELISA and bactericidal serogroup A meningococcal antibodies to determine concentrations that protect against acquisition of carriage. No further blood samples will be collected. A rapid diagnostic test for malaria will be performed on any subject who is febrile or unwell and antimalarial treatment provided according to the national guidelines if it is positive. The results of these household studies will show the impact of vaccination on acquisition rates of carriage.
Similar cross-sectional and longitudinal surveys to those described above will be conducted approximately 6 and 18 months after the mass vaccination campaigns with the serogroup A meningococcal conjugate vaccine.
AMENDMENT TO ORIGINAL STUDY PROTOCOL:
研究设计
- 研究类型
- Interventional
- 分配方式
- Na
- 干预模型
- Single Group
- 主要目的
- Prevention
- 盲法
- None
入排标准
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Adults or children whose parent or guardian give consent to participate in the study
- •Adults or children who do not have a serious acute or chronic illness
排除标准
- •lack of consent given by an adult or the parent or guardian of a potentially eligible study child
- •Adults or children who have a serious acute or chronic illness
研究组 & 干预措施
Vaccination
Healthy volunteers before and after vaccination
干预措施: MenAfriVac™ (Biological)
结局指标
主要结局
Meningococcal carriage
时间窗: Prevalence of meningococcal carriage at six months after vaccination
Cross-sectional surveys will be conducted in approximately 5,000 age stratified subjects before and 6 and 18 months after vaccination with the meningococcal serogroup A conjugate vaccine to estimate the prevalence of meningococcal carriage. During each cross-sectional survey all household members in contact with an identified serogroup A carrier will be included in a household follow up study to investigate the impact of vaccination on the rates of acquisition of meningococcal carriage.
次要结局
- Meningococcal carriage(Prevalence of meningococcal carriage at 18 months after vaccination)