Efficacy of the serogroup B Neisseria meningitidis vaccine (4CMenB) in preventing experimental Neisseria gonorrhoeae urethral infection: a double-blind randomised controlled human challenge study protocol. - Waltmann A; Kronk C; Lapple D; Motley MP; Lin FC; Seña AC; Hobbs MM; Duncan JA (BMJ open, 2026)