Podcast: Immune Persistence After Primary Vaccination with MenQuadfi.

Abstract

Invasive meningococcal disease (IMD) remains a serious global health concern. Although incidence is generally low, the disease progresses rapidly and carries high fatality rates of 10-15%, with survivors often experiencing long-term sequelae including hearing loss, neurological impairment, or limb amputations. These consequences highlight the need for effective and durable vaccination strategies. IMD incidence and serogroup distribution vary geographically. The highest burden occurs in the African meningitis belt, historically dominated by serogroup A, though recent outbreaks have increasingly involved serogroups C, W, and X. In Europe, serogroup B is most common, particularly in infants and adolescents, while serogroup Y is rising among adults aged ≥ 65 years. These geographical and demographic differences underscore the importance of region-specific vaccination policies. Polysaccharide vaccines targeting serogroups A, C, W, and Y have played an essential role in outbreak control but are associated with certain limitations: they do not induce immune memory and are poorly immunogenic in infants. These limitations led to the development of conjugate vaccines, where polysaccharide antigens are linked to protein carriers to enhance immunogenicity and memory responses. Several quadrivalent conjugate vaccines (MenACWY), MenQuadfi^®, Menveo^®, and Nimenrix^®, are available, which target the same four serogroups, but differ in antigen composition and carrier proteins. However, access to meningococcal vaccines varies across regions. In this podcast, Professor Mika Rämet and Dr Mike Simon discuss the concept of immune persistence and its relevance for evaluating long-term protection provided by quadrivalent meningococcal vaccines. They review persistence data for MenQuadfi from recent clinical trials and a modeling study across multiple age groups and timepoints, comparing these findings with persistence data for other quadrivalent vaccines. Overall, the evidence supports the use of MenQuadfi as a MenACWY option, including for children, to help provide and maintain protection against IMD in the years following primary vaccination.Podcast available for this article. Supplementary material 1 (MP2 156850 kb).