Antibody persistence after conjugate meningococcal group A vaccination in Mali

马里 A 组结合型脑膜炎球菌疫苗接种后抗体持续存在

• 批准号: 8213030
• 负责人: Nicole Elaine Basta
• 金额: --
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-20 至 2012-03-16
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8213030
• 关键词: Address; African; Age; Antibodies; Antibody Formation; Blood specimen; Burkina Faso; Clinical Trials; Country; Data; Data Analyses; Data Collection; Disease; Disease Outbreaks; Dose; Epidemic; Future; Goals; Health protection; Immune response; Immunity; Immunoglobulin G; Individual; Life; Mali; Mass Vaccinations; Meningitis; Meningococcal meningitis; Meningococcal vaccine; Morbidity - disease rate; Neisseria meningitidis; Niger; Nutritional status; Participant; Polysaccharides; Population; Prevention; Prevention strategy; Preventive; Public Health; Questionnaires; Recording of previous events; Research Design; Risk Factors; Sampling; Seasons; Serum; Socioeconomic Status; Statistical Methods; Target Populations; Time; United Kingdom; Universities; Vaccination; Vaccines; Washington; age group; aged; bactericide; base; clinically significant; design; immunogenicity; low socioeconomic status; mortality; novel vaccines; pathogen; population based; prevent; prospective; response; success; vaccin protein; vaccination strategy

DESCRIPTION (provided by applicant): Meningitis epidemics, primarily caused by N. meningitidis serogroup A, occur annually during the dry season in the African meningitis belt, leading to significant morbidity and mortality among the 450 million people living in this region. The introduction of MenAfriVac, a newly developed conjugate meningococcal serogroup A vaccine, in Burkina Faso, Mali, and Niger in December 2010 was the first ever population-based, preventive mass-vaccination campaign against meningococcal meningitis in the meningitis belt and the first- ever nationwide use of this vaccine. While clinical trials have demonstrated that MenAfriVac induces a stronger immune response than polysaccharide meningococcal serogroup A vaccines, the duration of protection provided by MenAfriVac is currently unknown. The persistence of the serogroup A-specific serum bactericidal antibody (SBA) response and the IgG response, both accepted correlates of protection against invasive disease, are key determinants of whether the MenAfriVac mass-vaccination campaign will successfully prevent the deadly epidemics of meningitis that have occurred in the region for the past century. Our goal is to address a critical barrier to progress in the field by evaluating the impact of the MenAfriVac mass-vaccination campaign. Specifically, we will assess the duration of protection provided by the vaccine up to five years after the population-based, mass-vaccination campaign targeted to all individuals aged 1-29 years in Bamako, Mali. We will determine when, if at all, population-level immunity begins to wane up to five years after mass- vaccination. Additionally, we will determine the most effective vaccination strategy, which can then be implemented both in Mali and other countries of the African meningitis belt in the future. We will evaluate the antibody persistence following the MenAfriVac mass-vaccination campaign by collecting prospective immunogenicity data from a random sample of 800 residents of Bamako, Mali, aged 1- 29 years at 18 months, 36 months, and 54 months after mass vaccination. Specifically, we aim to: 1.) determine the proportion of individuals with protective levels of serogroup A-specific SBA and IgG both overall and by age at each of the three post-vaccination time points, 2.) evaluate the significance of temporal changes in serogroup A-specific SBA and IgG titers both overall and by age up to five years post-vaccination, and 3.) assess potential risk factors, such as age at vaccination, prior polysaccharide meningococcal vaccination, nutritional status, and socioeconomic status, for low SBA and IgG titers at each of the three post-vaccination time points. Statistical methods will be used to provide evidence for the degree of vaccine-induced antibody persistence and to evaluate risk factors for low antibody response. The results will be used to develop and implement the most effective vaccination strategy in the countries of the African meningitis belt, to determine if there is a need for additional booster doses of vaccine in any age group after five years, and to increase our understanding of the mechanism by which MenAfriVac provides protection against invasive disease. PUBLIC HEALTH RELEVANCE: Seasonal meningitis outbreaks caused primarily by Neisseria meningitidis serogroup A are responsible for significant morbidity and mortality among the nearly 450 million people living in the African meningitis belt. In December 2010, the first-ever preventive meningitis mass-vaccination campaign using a newly developed conjugate meningococcal serogroup A vaccine was launched in this region. We aim to evaluate the persistence of the protective antibody response generated by this vaccine in Bamako, Mali, for up to five years post-vaccination. Our goal is to determine the most effective vaccination strategy capable of maintaining protective levels of immunity in the population and ending the devastating epidemics of meningitis.

描述（由申请人提供）：脑膜炎流行病主要由脑膜炎血清群A引起，每年在非洲脑膜炎带的干旱季节发生，导致居住在该地区的4.5亿人中的发病率和死亡率很高。 2010年12月，在布基纳法索，马里和尼日尔的梅纳夫瓦克（Menafrivac）引入了新开发的共轭脑膜炎球菌血清群A疫苗，这是有史以来首次基于人口的预防性大规模疫苗接种运动，反对脑膜炎脑膜炎脑膜炎的脑膜炎脑膜炎和脑膜炎带和该疫苗的首次使用。虽然临床试验表明，梅纳弗里瓦克（Menafrivac）诱导的免疫反应比多糖脑膜炎球菌血清群A疫苗更强，但梅纳弗利瓦克（Menafrivac）提供的保护持续时间目前尚不清楚。血清群A特异性血清杀菌抗体（SBA）反应的持久性和IgG反应（两者都接受保护侵袭性疾病的保护相关性）是Menafrivac群众疫苗接种运动的关键决定因素，是否成功地阻止了过去一世纪发生的脑膜病的致命流行病。我们的目标是通过评估MENAFRIVAC大众疫苗接种运动的影响来解决该领域进步的关键障碍。具体而言，我们将评估疫苗在基于人群的大规模疫苗接种运动后五年内提供的保护持续时间，该运动针对马里巴马科（Bamako）的所有1-29岁以上的个人。我们将确定何时在大规模疫苗接种后五年内，何时开始减少人口水平的免疫力。此外，我们将确定最有效的疫苗接种策略，然后将来可以在马里和其他非洲脑膜炎带的其他国家实施。我们将通过从马里（Mali）的800名居民中随机样本收集前瞻性免疫原性数据来评估MENAFRIVAC大规模疫苗接种运动后的抗体持久性，在18个月，36个月和54个月后，在Mali的800名居民中，年龄1-29岁。具体而言，我们的目的是：1。）确定在三个疫苗接种后时间点中，具有保护性水平A的全面和IgG的保护性水平的个体和IgG的比例。2。）评估时间变化的时间变化的重要性在疫苗接种后的三个时间点中，脑膜炎球菌疫苗接种，营养状况和社会经济状况，对于低SBA和IgG滴度。统计方法将用于为疫苗诱导的抗体持久性的程度提供证据，并评估低抗体反应的危险因素。结果将用于制定和实施非洲脑膜炎带国家中最有效的疫苗接种策略，以确定在五年后任何年龄段的任何年龄段中是否需要额外的促进剂量疫苗，并提高我们对Menafrivac提供保护侵袭性疾病的机制的理解。 公共卫生相关性：主要由奈瑟氏菌脑膜炎造成的季节性脑膜炎暴发，造成了近4.5亿居住在非洲脑膜炎带的近4.5亿人中的显着发病率和死亡率。 2010年12月，使用新开发的共轭脑膜炎球菌血清群A疫苗进行的首次预防性脑膜炎大规模疫苗接种运动是在该地区发射的。我们的目的是评估该疫苗在马里的巴马科产生的保护性抗体反应的持久性，在疫苗接种后长达五年。我们的目标是确定能够维持人群保护性免疫力的最有效疫苗接种策略，并结束脑膜炎的毁灭性流行病。