A seroprevalence study for Neisseria meningitidis serogroups A and X to advance introduction of ACWYX conjugate meningococcal vaccines in Ethiopia

Summary

One of the most successful public health interventions of recent times was the introduction of serogroup A meningococcal conjugate vaccine (MenA) in the African ‘meningitis-belt’ to control epidemic meningitis. However, the programme now faces two threats; many countries (Ethiopia included) did not follow up the mass campaigns in 2013-15 by introducing MenA vaccine into the routine immunisation system leaving many birth cohorts of children unvaccinated and susceptible; sporadic meningitis caused by other serotypes (W, C and X) has crept in through spread from adjacent non-meningitis-belt countries.

In this project we propose to describe the seroprevalence of IgG to meningococcal serogroups A and X through two random surveys of 1000 people of all ages – one in the ‘meningitis-belt’ in the West and one in the more ecologically diverse East. Using a serogroup-specific ELISA, we will examine antibody persistence in birth cohorts vaccinated in the mass campaign; and we will look for evidence of circulation of MenX in antibody prevalence in the whole population. The project represents excellent value because it will be conducted on the back of a Gates-Foundation-funded survey of meningococcal carriage. A new partnership was established between Ethiopian (Assefa/Regassa) and International (Trotter/Scott) scientists to examine meningococcal epidemiology, and this will be further enriched by Ray Borrow of UKHSA to support immunoassays. The investigators have strong links with the Ethiopian Public Health Institute through which they hope to advocate for new meningococcal vaccine policy.