Efficacy Trial on Meningococcal B Vaccine for Preventing Gonorrhea Infections

Efficacy of a Meningococcal B Vaccine Against Neisseria Gonorrhoeae Infections Among Men Who Have Sex With Men: a Randomised-controlled Clinical Trial

Objectives: Efficacy of a meningococcal vaccine against Neisseria gonorrhoea (NG) infection among men who have sex with men (MSM).

Design: Parallel randomised double-blind placebo-controlled trial.

Setting: A teaching hospital in Hong Kong.

Participants: 150 adult MSM at risk of gonorrhoea infection (condomless sex with more than one man within the last six months, history of sexually transmitted infection [STI] diagnosis, inclination to have condomless sex, and other PrEP-eligible criteria) would be recruited into the trial, with half allocated to intervention and control group each.

Intervention: Intervention and control group would receive, one month apart, two doses of meningococcal vaccine and normal saline, respectively.

Main outcome measures: Safety and efficacy of vaccine against gonorrhoea (time to first gonorrhoea infection and incidence), and behavioural change after vaccination.

Expected results: NG incidences in two groups would be compared. Efficacy of vaccine against gonorrhoea would be determined after controlling confounding variables. Characteristics of participants with incident NG would be distinguished from those without incident infections. Change of frequency of sexual activities and networking would be noted.

Implications: Strategies on STI screening and vaccination could be informed. Reduced STI burden post-vaccination could be measured with surveillance system.

Study Overview

• Status: Active, not recruiting
• Conditions: Gonorrhea; Sexually Transmitted Infection
• Intervention / Treatment: Biological: 4CMenB vaccine; Other: Placebo

• Study Type: Interventional
• Enrollment (Estimated): 150
• Phase: Phase 3

Contacts and Locations

Study Locations

• Hong Kong
  • Shatin, Hong Kong
    • Stanley Ho Centre for Emerging Infectious Diseases

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 50 years (Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Male adult who has had sex with another male in the past six months
• Ages 18 years or above
• Normally resides in Hong Kong
• Able to communicate in written and spoken Chinese or English
• At risk of gonorrhoea infection (had condomless sex with more than one man within the last six months, history of STI diagnosis, inclination to have condomless sex, and other PrEP-eligible criteria)
• Negative NG test result at the time of recruitment
• No history of previous vaccination with MenB vaccines
• Able and willing to attend all study visits

Exclusion Criteria:

• Contraindications to receive MenB vaccine
• Unable to give informed consent

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Intervention; Intramuscular injection of 2 doses of 0.5mL 4CMenB vaccine 1 month apart	Biological: 4CMenB vaccine; Four-component MenB vaccine; Other Names: Bexsero
Placebo Comparator: Control; Intramuscular injection of 2 doses of 0.5mL placebo 1 month apart	Other: Placebo; 0.9% Sodium Chloride Inj. B.P.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Comparison between incidence of NG between two groups	Difference in NG incidences in the two groups	Month 2 to Month 24

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in risk behaviours and networking pattern after vaccination	Frequency of sex networking, number of sex partners, and use of condoms	Month 2 to Month 24
Safety profile of the vaccine	Prevalence of adverse events	Month 2 to Month 24

Collaborators and Investigators

• Sponsor: Chinese University of Hong Kong
• Investigators: Principal Investigator: Tsz Ho Kwan, PhD, Jockey Club School of Public Health and Primary Care

Study record dates

Study Major Dates

• Study Start (Actual): May 4, 2023
• Primary Completion (Estimated): September 1, 2026
• Study Completion (Estimated): December 1, 2026

Study Registration Dates

• First Submitted: March 1, 2023
• First Submitted That Met QC Criteria: March 11, 2023
• First Posted (Actual): March 13, 2023

Study Record Updates

• Last Update Posted (Actual): March 19, 2026
• Last Update Submitted That Met QC Criteria: March 17, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Urogenital Diseases; Genital Diseases; Pathologic Processes; Disease Attributes; Infections; Communicable Diseases; Bacterial Infections; Bacterial Infections and Mycoses; Gram-Negative Bacterial Infections; Sexually Transmitted Diseases, Bacterial; Neisseriaceae Infections; Pathological Conditions, Signs and Symptoms; Sexually Transmitted Diseases; Gonorrhea; 4CMenB vaccine
• Other Study ID Numbers: 21200912

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No