UNSW Kirby Institute

CROI 2026: Meningococcal B vaccine shows no protection against gonorrhoea

March 2, 2026

Results from what authors describe as the world’s largest randomized controlled trial evaluating the meningococcal B vaccine (4CMenB) for gonorrhoea prevention show no reduction in infection among gay and bisexual men, the study’s focus due to their elevated risk of acquiring gonorrhoea. In this double‑blind, placebo‑controlled trial of 587 participants, annual gonorrhoea incidence was nearly identical between vaccine and placebo groups at about 48%. Findings were presented at the Conference on Retroviruses and Opportunistic Infections in Denver, CO. These results counter earlier observational evidence and align with the smaller DOXYVAC trial, reinforcing that 4CMenB does not prevent gonorrhoea acquisition.

Clinical takeaway: The vaccine remains safe and effective against meningococcal disease, but clinicians should advise patients that it offers no protection against gonorrhoea and emphasize established preventive measures such as condom use and regular STI screening.

Source:

(2026, February 25). UNSW Kirby Institute. Meningococcal B vaccination does not reduce gonorrhoea, trial results show [News release]. https://www.kirby.unsw.edu.au/about/kirby-institute