Efficacy of Immunization With 4C-MenB in Preventing Experimental Urethral Infection With Neisseria Gonorrhoeae

The study is a single-site, double-blind randomized controlled trial to test whether vaccination with 4C-MenB, BEXSERO™ (approved for protection against invasive disease with group B Neisseria meningitidis), according to the FDA-approved schedule , provides protection from urethral infection with Neisseria gonorrhoeae in the controlled human male gonococcal infection model. The study will be conducted in 3 phases: 1) initial vaccination phase, 2) Neisseria gonorrhoeae challenge phase, and 3) post-challenge vaccination phase. The study intervention is vaccination with two doses of BEXSERO™ and two commercially available FDA-approved vaccines that do not have relevance to Neisseria gonorrhoeae: quadrivalent influenza (FLULAVAL™) and tetanus/diphtheria (TDVAX™). At enrollment, participants are randomized in a 1:1 ratio to the control vaccine arm or the experimental vaccine arm. All participants receive two immunizations prior to the bacterial challenge phase and two immunizations in the post-challenge phase. Individuals assigned to the experimental arm receive two doses of BEXSERO™ prior to Neisseria gonorrhoeae challenge and control vaccines in the post-challenge vaccination phase. Participants assigned to the control arm receive FLULAVAL™ and TDVAX™ prior to challenge and BEXSERO™ in the post-challenge vaccination phase. Primary and secondary outcomes are determined following bacterial challenge. This study design provides clinical equipoise, because all participants receive the known benefits associated with administration of BEXSERO™ for protection against meningococcal disease. For bacterial challenge, all participants receive a suspension containing 10\^6 colony-forming units of Neisseria gonorrhoeae strain FA1090 delivered to the anterior urethra. This dose has been shown to produce symptomatic gonococcal urethritis in 80-90% of unvaccinated, exposed participants within 5 days after bacterial inoculation. Participants are followed with daily visits to assess for development of urethritis and presence of Neisseria gonorrhoeae in their urine. Participants receive 100% effective antibiotic treatment when (1) requested by the participant regardless of signs, symptoms or positive cultures, (2) urethral discharge is observed by the examining clinician or reported by the participant, or (3) 10 days after urethral inoculation with bacterial product, regardless of infection status.