Implications of differential age distribution of disease-associated meningococcal lineages for vaccine development

Area of Science:

• Microbiology and Immunology
• Vaccinology
• Epidemiology

Background:

• New vaccines targeting serogroup B meningococci are emerging, with some approved in Europe.
• Vaccine coverage is influenced by the distribution of disease-causing genotypes, which can differ across age groups.
• Hyperinvasive lineages, specific genetic groups of meningococci, are known to cause the majority of invasive meningococcal disease (IMD) and are linked to particular antigens relevant for vaccine development.

Purpose of the Study:

• To investigate the age-specific distribution of hyperinvasive meningococcal lineages.
• To inform the development and implementation of vaccines targeting *Neisseria meningitidis* serogroup B.

Main Methods:

• Multilocus sequence typing (MLST) was used to characterize 4,048 meningococcal disease isolates from 18 European countries over 3 years.
• Age data were available for 3,147 isolates.
• Analysis focused on identifying clonal complexes (ccs) and sequence types (STs) associated with disease in different age demographics.

Main Results:

• Significant differences in the proportions of hyperinvasive lineages were observed across age groups.
• Infants (<1 year) had lower risks of ST-11 cc, ST-32 cc, and ST-269 cc disease, but higher risks from unassigned STs.
• Adolescents and young adults were more associated with specific clonal lineages, while younger and older individuals were vulnerable to a broader range of genotypes.

Conclusions:

• The age-specific distribution of hyperinvasive meningococcal lineages necessitates tailored vaccine strategies.
• Understanding the population dynamics and genetic diversity of meningococci is crucial for effective vaccine-mediated disease control.
• Different vaccine variants or targets may be required to achieve optimal coverage across all age groups.