Impact and effectiveness of meningococcal vaccines: a review

Objectives. To summarize and critically evaluate the evidence on the impact and effectiveness of meningococcal vaccination programs around the world in order to inform decision-making in Latin America and the Caribbean. Methods. A review of the literature was conducted following several components of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. PubMed Central (R) was searched for papers published in any language from January 1999 - March 2017. Results. In all, 32 studies were included, most of which evaluated the meningococcal C conjugate vaccine. Fourteen studies measured effectiveness and 30 measured impact. The effectiveness of polysaccharide vaccines was 65% - 83.7% (different age groups), while the effectiveness of the conjugate vaccines was 66% - 100%. Incidence decline of laboratory-confirmed meningococcal disease for the conjugate vaccine ranged from 77% - 100% among different ages groups. The only study that evaluated the protein subunit vaccine reported a vaccine effectiveness of 82.9%. Conclusions. The studies reviewed show impact and effectiveness of both polysaccharide vaccines and conjugate vaccines on vaccine-serogroup meningococcal disease. The conjugate vaccines, however, show higher impact and effectiveness with longer-lasting protection over the polysaccharide vaccines. Given the variance in potential use of a meningococcal vaccine, epidemiological surveillance systems should be strengthened to inform national decisions.