TOPLINE

Meningococcal B vaccine (4CMenB) was associated with lower risk for gonorrhea among adolescents in the Northern Territory in Australia. The vaccine did not reduce overall meningococcal carriage, but disease-associated carriage remained stable.

METHODOLOGY

• A multidesign study evaluated effectiveness of 4CMenB vaccine against gonorrhea and impact on oropharyngeal meningococcal carriage in adolescents and young people in Australia's Northern Territory and Ngaanyatjarra Lands.
• For the vaccine effectiveness analysis, investigators used a rolling cohort design with linked notification and immunization data from 30,650 individuals aged 15-19 years between March 2021 and February 2024.
• For the carriage study, 2526 participants (median age, 16.2 years) receiving 4CMenB vaccination were enrolled; oropharyngeal swabs were screened for N. meningitidis using polymerase chain reaction detection of porA and ctrA genes at baseline and follow-up (median 370 days between visit 1 and visit 3).
• The study outcomes included time to first gonococcal infection (measured by hazard ratio [HR]) and change in meningococcal carriage prevalence between baseline and follow-up visits.

TAKEAWAY

• Adjusted vaccine effectiveness against gonorrhea was 38.4% (adjusted hazard ratio [aHR], 0.62; P < .001) after 2 doses of 4CMenB and 26.7% (aHR, 0.73; P = .075) after one dose in the overall population.
• Female adolescents had greater apparent benefit than males after two doses, with vaccine effectiveness of 45.9% vs 25.0%, respectively.
• Carriage of Neisseria meningitidis increased significantly from baseline to follow-up: 4.0% to 6.2% (odds ratio [OR], 1.68; P = .01); disease-associated meningococcal carriage stayed stable: 1.5% to 1.4% (OR, 1.21; P = .66)
• Risk factors for gonococcal infection included Aboriginal and Torres Strait Islander status (adjusted OR [AOR], 30.16; P < .001), female sex (AOR, 1.71; P < .001), and residence in remote regions compared with urban areas.

IN PRACTICE

"The results demonstrate that the 4CMenB vaccine provides modest protection against gonorrhea in a real-world setting, in a population with a higher prevalence of gonorrhea and where rates are higher among women than men," the study authors wrote. "This finding is particularly significant given the potential for serious complications in women, particularly very young women, such as pelvic inflammatory disease, tubal scarring, ectopic pregnancy, and infertility, especially as most infections are asymptomatic."

SOURCE

The study was led by Mark McMillan, Robinson Research Institute and Adelaide Medical School, The University of Adelaide in Adelaide, South Australia, Australia. It was published online on August 4, 2026, in Open Forum Infectious Diseases.

LIMITATIONS

Vaccine uptake was lower than expected, which reduced study power. Behavioral risk data, prior sexually transmitted infection history, and sexually transmitted infection testing frequency were not available. Residual confounding may have affected the gonorrhea analysis. The carriage study had a small sample size and 57.0% missing 12-month swab data.

DISCLOSURES

The study was supported by grants from the National Health and Medical Research Council (NHMRC), multiple Australian universities including the University of Adelaide, University of Queensland, University of New South Wales, Menzies School of Health Research, University of Sydney, and University of Western Australia, as well as SA Health, Aboriginal Medical Services Alliance of the Northern Territory, Clinical Research and Development Board, Hospital Research Foundation, and Women's and Children's Hospital Foundation. Several authors reported receiving research support, consulting fees, or grants from pharmaceutical companies including GSK, Pfizer, Sanofi Pasteur, and Seqirus, with some serving as investigators for vaccine trials. Additional author disclosures are reported in the original article.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.