Cross-protection of meningococcal B vaccines against gonorrhea: A systematic review and Meta-analysis

Introduction: Gonorrhea remains a major global public health challenge due to its rising incidence, association with severe complications, and growing antibiotic resistance. Vaccine development against N. gonorrhoeae presents a promising solution, with particular focus on leveraging existing vaccines that offer potential cross-protective effects. This study evaluates the potential effectiveness of outer membrane vesicle (OMV)-based meningococcal B vaccines in preventing N. gonorrhoeae infections. Method(s): A systematic search was performed in PubMed, Embase and Scopus with no language restrictions until December 10th, 2024. Data were extracted independently by two researchers and effect estimates were synthesized using a random-effects model. We sought for odds ratios, relative risks, hazard ratios, or prevalence ratios of N. gonorrhoeae diagnoses between recipients of OMV-based vaccines and either unvaccinated individuals or those vaccinated with other vaccines. Vaccine effectiveness (VE) was calculated as (1 - Effect Size [ES]) x 100 %. Subgroup analyses by comparator, intervention (type of OMV-based MenB vaccine administered and number of doses) and type of effect estimate were conducted. Result(s): Nine out of 814 screened items met the inclusion criteria; all of them were observational (three cohort and five case-control studies) except one randomized clinical trial (RCT). OMV-based meningococcal B vaccination was linked to a statistically significant reduction in N. gonorrhoeae diagnoses overall (pooled ES: 0.70, 95 % CI: 0.61-0.81, p < 0.001), namely pooled vaccine effectiveness (VE) estimated at 30 % (95 %CI: 19 %-39 %). Conclusions and relevance: While randomized clinical trials are necessary, the findings of this systematic review and meta-analysis highlight the potential effectiveness of OMV-based vaccines in terms of gonorrhea prevention. Copyright © 2025