Background
Observational evidence suggests the 4CMenB meningococcal vaccine may partially protect against gonorrhea, with 1 dose being two-thirds as protective as 2 doses. We examined the cost-effectiveness of vaccinating men who have sex with men (MSM) in England, with 1- or 2-dose primary vaccination.

Methods
Integrated transmission-dynamic health-economic modeling explored the effects of targeting strategy, first- and second-dose uptake levels, and duration of vaccine protection, using observational estimates of vaccine protection.

Results
Vaccination with 1 or 2 primary doses is always cost-saving, irrespective of uptake, although vaccine sentiment is an important determinant of impact and cost-effectiveness. The most impactful and cost-effective targeting is offering “vaccination according to risk” (VaR), to all patients with gonorrhea plus those reporting high numbers of sexual partners. If VaR is not feasible to implement then the more restrictive strategy of “vaccination on diagnosis” (VoD) with gonorrhea is cost-effective, but much less impactful. Under conservative assumptions, VaR (2-dose) saves £7.62M (95% credible interval [CrI], 1.15–17.52) and gains 81.41 (95% CrI, 28.67–164.23) quality-adjusted life-years (QALYs) over 10 years; VoD (2-dose) saves £3.40M (95% CrI, .48–7.71) and gains 41.26 (95% CrI, 17.52–78.25) QALYs versus no vaccination. Optimistic versus pessimistic vaccine-sentiment assumptions increase net benefits by approximately 30% (VoD) or approximately 60% (VaR).

Conclusions
At UK costs, targeted 4CMenB vaccination of MSM gains QALYs and is cost-saving at any uptake level. Promoting uptake maximizes benefits and is an important role for behavioral science.