Efficacy Trial on Meningococcal B Vaccine for Preventing Gonorrhea Infections

Study Overview
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Brief Summary
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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.

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

Conditions
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Gonorrhea, Sexually Transmitted Infection

Intervention / Treatment
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* Biological: 4CMenB vaccine
* Other: Placebo


Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 50 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Participants in the vaccination group would receive two doses of 4CMenB vaccine 1 month apart (at Month 0 and Month 1) while subjects in the control group would receive two doses of normal saline of a similar volume.
Masking: Quadruple


Arms and Interventions

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

What is the study measuring?
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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 |