Meningococcal vaccines Shows effectiveness in high risk gonorrhea patients: Study

A recent systematic review revealed that meningococcal vaccines that target the B strain (MenB) show moderate effectiveness in preventing gonorrhoea. This finding published in the Journal of Infection marked a significant step forward in effectively managing the sexually transmitted infection which is increasingly resistant to antibiotics.

The review evaluated studies that were retrieved from PubMed, Embase, Cochrane Library and CINAHL along with clinical trial registries and major health and immunisation conferences. Following this, a total of 12 studies met the criteria for inclusion in the analysis. 9 of these studies focused on the effectiveness of MenB outer membrane vesicle (OMV) vaccines where one study evaluated a non-OMV vaccine, MenB-FHbp. The primary target group for these studies was individuals of the ages 15 to 30 years who are at risk for gonorrhoea. The adjusted vaccine effectiveness (VE) for OMV vaccines against gonorrhoea ranged from 22% to 46% that indicated a moderate level of protection. Also, the MenB-FHbp vaccine did not show any significant protection against the infection.

One of the key finding from this meta-analysis was that the pooled VE estimates for OMV vaccines against any gonorrhoea infection following the full vaccine series were around 33 to 34%. This demonstrated that while the vaccines do not offer complete protection, they do reduce the risk of contracting gonorrhoea. The impact (VI) of MenB vaccines on gonorrhoea incidence was also assessed in the review. Also, the vaccines 4CMenB, VA-MENGOC-BC and MenBvac were evaluated in Canada, Australia, Cuba and Norway, respectively. The results showed a reduction in gonorrhoea incidence that ranged from 30% to 59% following vaccination. This variation highlighted the potential of these vaccines to greatly decrease the number of gonorrhoea cases in different populations.

The findings suggest that MenB-OMV vaccines, including 4CMenB, could be a valuable in managing gonorrhoea. However, the moderate effectiveness observed also illuminate the need for continued research to better understand the factors that influence vaccine protection. While meningococcal B vaccines are not a cure for gonorrhoea, their moderate effectiveness represents a promising avenue for reducing the burden of this infection. The studies analyzed showed varying levels of vaccine effectiveness with adjusted VE for OMV vaccines which ranged between 22% to 46%. This range indicated that while some vaccinated individuals still contracted gonorrhoea, but, the risk was significantly reduced when compared to the unvaccinated individuals. 

Overall, the outcome of this review suggest that future research should focus on identifying the underlying mechanisms that contribute to the protective effects of these vaccines. This knowledge could help in developing more effective vaccination strategies which could lead to increased rates of prevention and better control of gonorrhoea outbreaks.

Reference:

Wang, B., Mohammed, H., Andraweera, P., McMillan, M., & Marshall, H. (2024). Vaccine effectiveness and impact of meningococcal vaccines against gonococcal infections: A systematic review and meta-analysis. In Journal of Infection (p. 106225). Elsevier BV. https://doi.org/10.1016/j.jinf.2024.106225