The MenB-4C vaccine is moderately effective against gonorrhea

The MenB-4C vaccine, an outer membrane vesical-based serogroup B meningococcal vaccine, is moderately effective against gonorrhea in various populations, according to study results published in The Journal of Infectious Diseases.

Researchers conducted a systematic review and meta-analysis to synthesize literature published on MenB-4C vaccine effectiveness against gonorrhea. Databases were searched for peer-reviewed manuscripts published in English between January 2013 and July 2024 that assessed the effectiveness of the MenB-4C vaccine against gonorrhea and gonorrhea/chlamydia coinfection, as well as the duration of vaccine-induced protection. A DerSimonian-Laird random effects model was used to estimate pooled vaccine effectiveness against gonorrhea.

A total of 8 articles were included in the analysis, 4 of which were conducted in the US, 2 of which were conducted in Australia, 1 of which was conducted in Italy, and 1 of which was conducted in France. Data sources included linked sexually transmitted infection (STI) surveillance and immunization information system records, electronic health records, and a randomized clinical trial. The unit of analysis of vaccine effectiveness was person- and infection-level in 5 and 3 studies, respectively.

Estimates of vaccine effectiveness against gonorrhea among adolescents and young adults aged 15 to 30 ranged from 23% to 47% in 7 observational studies. Two studies demonstrated that 2 vaccine doses were 32% to 33% effective against gonorrhea in adolescents and young adults aged 15 to 25. In a study of adult men who have sex with men living with HIV and in HIV care, 2 doses of vaccine were 44% effective gonorrhea. In another study, 2 doses vs no doses of vaccine were 40% effective against gonorrhea, while 1 dose vs no doses of vaccine was 26% effective.

Based on 9 estimates from 8 studies, pooled vaccine effectiveness against gonorrhea following at least 1 dose of vaccine was 32.4% (95% CI, 26.2-38.7). No publication bias or study heterogeneity was observed.

In a sensitivity analysis of 7 observational studies, pooled vaccine effectiveness against gonorrhea following at least 1 dose of vaccine was 33.5% (95% CI, 26.9-40.1). Similarly, no publication bias or study heterogeneity was observed.

A total of 4 studies assessed the effectiveness of the MenB-4C vaccine against gonococcal mono-infections. Two doses of vaccine were 31.6% and 28.3% effective against mono-infection according to 2 studies. Another study demonstrated that 2 doses and 1 dose were 40% and 26% effective against mono-infection, respectively. The fourth study found that at least 1 dose of vaccine was 23% effective against mono-infections.

The effectiveness of the MenB-4C vaccine against gonorrhea/chlamydia coinfection was considered in 4 studies. Two studies demonstrated that 2 vaccine doses were 32.7% and 44.7% effective against coinfection. Another 2 other studies indicated that the vaccine was not effective against coinfection.

According to 1 study that assessed the duration of protection of 2 doses of vaccine against gonorrhea, effectiveness against gonorrhea within 6 to 36 months postvaccination vs more than 36 months postvaccination was significantly higher (34.9% vs 23.2%, respectively). Two other studies with median follow-up periods of 37 months and 45 months demonstrated 2-dose effectiveness of 40% and 44%, respectively.

Study limitations include the exclusion of articles that were not published in English, small sample size, reduced generalizability of results, and potential reporting and misclassification biases.

“Data from ongoing clinical trials that are evaluating the efficacy of MenB-4C vaccine against gonorrhea (genital and extragenital) and gonorrhea/chlamydia coinfection and investigating a correlate of immune protection are urgently needed,” the researchers concluded.

By Paul Basilio

References:

Abara WE, Kirkcaldy RD, Bernstein KT, Galloway E, Learner ER. Effectiveness of MenB-4C vaccine against gonorrhea: a systematic review and meta-analysis. J Infect Dis. Published online July 31, 2024. doi:10.1093/infdis/jiae383