Defining seroprevalence and correlates of protection for Neisseria meningitidis group A in the African meningitis belt

我们正在努力找出更多有关保护人们免受由“A群脑膜炎球菌”细菌引起的脑膜炎的因素。这种疾病的大规模、毁灭性流行发生在非洲撒哈拉以南地区，称为“脑膜炎带”。目前正在研制一种针对这种疾病的疫苗，并将于2009年在布基纳法索首次使用。接种疫苗的人在血液中产生抗体，保护他们免受这种形式的脑膜炎。我们也知道，有些人如果在一生中接触过这种细菌，就会自然产生抗体。虽然我们可以测量这些抗体，但我们不知道需要多少抗体才能起到保护作用。为了研究这一点，我们将从布基纳法索未接种疫苗的人身上采集血液样本，并比较不同年龄组中抗体超过一定阈值的人患脑膜炎的几率。如果我们能够确定这种保护标记，我们将帮助科学家解决其他重要问题，例如人群应该多久接种一次疫苗以保持对疾病的保护。此外，我们将收集血液样本，供其他研究人员用于研究非洲其他类型的脑膜炎。

We are trying to find out more about the factors that protect people against meningitis caused by bacteria known as ‘group A meningococcus’. Large, devastating epidemics of this disease occur in Africa in a sub-Saharan region called the ‘meningitis belt’. A vaccine is being developed against this disease, and will be first used in Burkina Faso in 2009.People who are vaccinated produce antibodies in their blood that protect them from this form of meningitis. We also know that some individuals can develop antibodies naturally if they are exposed to the bacteria during the course of their life. Although we can measure these antibodies we do not know what levels are needed for protection. To study this, we are going to take blood samples from unvaccinated individuals in Burkina Faso and compare the proportion of people in different age groups who have antibodies above a certain threshold with their chances of getting meningitis. If we can define this marker of protection, we will help scientists address other important questions, such as how often populations should be vaccinated to maintain protection against the disease. In addition, we will create a collection of blood samples that can be used by other researchers to study other types of meningitis in Africa.