Three randomised trials found no gonorrhoea protection from the vaccine England still offers

A vaccine that England has been offering since 1 August 2025 to prevent gonorrhoea does not prevent gonorrhoea, at least not in the men most likely to catch it. That is the finding of GoGoVax, a phase 3 double blind placebo controlled trial published in the New England Journal of Medicine on 8 July 2026, and it is the third randomised trial in a row to reach broadly the same conclusion.

GoGoVax randomised 654 gay and bisexual men, trans women and non binary people who have sex with men across seven Australian sexual health clinics in Sydney, Melbourne and the Gold Coast, with 587 included in the primary per protocol analysis. Everyone enrolled had been diagnosed with gonorrhoea or infectious syphilis in the preceding 18 months. They received two doses of 4CMenB, the four component meningococcal B vaccine sold as Bexsero, or a matching placebo three months apart, then returned every three months for two years for nucleic acid amplification testing of urogenital, anorectal and oropharyngeal samples.

The result was as close to nothing as a trial can produce. Gonorrhoea incidence was 48.1 events per 100 person-years in the vaccine group and 47.8 in the placebo group, an incidence rate ratio of 1.01 (95 per cent confidence interval 0.80 to 1.26, P equals 0.97). Vaccine efficacy was minus 0.5 per cent, with a confidence interval running from minus 26.2 to 19.9. It was no better broken down by site: minus 20.0 per cent for urogenital infection, minus 1.2 per cent anorectal, 2.6 per cent oropharyngeal. Serious adverse events occurred in 4.7 per cent of the vaccine group and 2.8 per cent of the placebo group. The trial was funded by Australia's National Health and Medical Research Council and by GSK, which manufactures Bexsero, and is registered as NCT04415424.

Two other randomised trials point the same way. MenGO, a smaller open label trial of 130 gay and bisexual men at the Gold Coast Sexual Health Clinic, returned an incidence rate ratio of 0.78 (95 per cent CI 0.40 to 1.51, p equals 0.457). The French DOXYVAC trial reported an adjusted hazard ratio of 0.78 (95 per cent CI 0.60 to 1.01, p equals 0.061), an efficacy estimate of 22 per cent that did not reach statistical significance.

The awkwardness is that England built a national programme on the earlier evidence. The Joint Committee on Vaccination and Immunisation advised on 10 November 2023 that a targeted 4CMenB programme be offered opportunistically through sexual health services to those at greatest risk. Its evidence base was observational: studies from Canada, Australia, the United States, Italy and New Zealand, animal work, and the genetic homology between Neisseria meningitidis and Neisseria gonorrhoeae. It cited real world effectiveness estimates of 32.7 to 42 per cent. It cited no randomised trial, because none had reported.

The UK Health Security Agency has not withdrawn the programme. Its frequently asked questions document, updated on 31 July 2026, discusses all three trials by name and concedes the hierarchy of evidence, noting that the protective effects identified so far rest on observational evidence "which is considered to be evidence of lower quality than randomised controlled trials". It offers a defence: that the very high rates of prior gonorrhoea among trial participants "make them less susceptible to any potential protective effects of vaccination". The same document still quotes a 2024 meta-analysis giving pooled effectiveness of 34 per cent in case control studies and 33 per cent in cohort studies. The NHS patient page for the vaccine, as published, tells people that after two doses it "provides around 30% to 40% protection against gonorrhoea".

Kate Seib of Griffith University and Andrew Grulich of the Kirby Institute, who led GoGoVax, wrote in a review in the Journal of the International AIDS Society in July 2026 that a meta-analysis of the observational data had estimated a 38 per cent risk reduction (95 per cent CI 28 to 48), that programmes were launched in Galicia, Spain, and the United Kingdom during 2025 on that basis, and that the United Kingdom may now need to reconsider its recommendations.

What is not settled is why the two bodies of evidence disagree. Confounding in the observational studies is one candidate, prior exposure blunting any vaccine effect is another, and neither has been demonstrated. Further randomised trials are running in women and in people at lower risk of acquisition, and their results will determine whether 4CMenB does anything useful in populations unlike the one GoGoVax recruited. Nobody has yet published how many people in England have been vaccinated under the programme, or what UKHSA's own surveillance of it, set up in November 2025, has so far found.