Real-world impact and effectiveness of MenACWY-TT.

Area of Science:

• Immunology
• Epidemiology
• Public Health

Background:

• Escalating cases of serogroup W invasive meningococcal disease (IMD) prompted vaccine program changes.
• Quadrivalent conjugate MenACWY vaccines were introduced into national immunization programs (NIPs) in response to rising MenW incidence.

Purpose of the Study:

• To summarize real-world impact and vaccine effectiveness (VE) data of the MenACWY-TT vaccine.
• To assess the effectiveness of MenACWY-TT in reducing IMD incidence across different countries and age groups.

Main Methods:

• Extracted incidence rate reductions (IRRs) and VE data from published literature.
• Analyzed data from Chile, England, the Netherlands, and Australia post-NIP implementation.
• Calculated IRRs and VE from baseline to post-NIP periods.

Main Results:

• Substantial IRRs of MenCWY observed in vaccine-eligible (83%-85%) and non-vaccine-eligible (45%-53%) age groups after a single MenACWY-TT dose.
• Impact primarily driven by MenW reductions in both vaccine-eligible (65%-92%) and non-vaccine-eligible (41%-57%) populations.
• High VE against MenW reported in toddlers (92%) and adolescents/young adults (94%).

Conclusions:

• Real-world data support the implementation and continued use of MenACWY-TT in NIPs.
• MenACWY-TT demonstrates significant effectiveness in controlling MenW-driven IMD.
• Indirect protection observed in non-vaccinated age groups highlights herd immunity benefits.