GonorrheaPhase 3NCT05766904
Efficacy Trial on Meningococcal B Vaccine for Preventing Gonorrhea Infections
A Phase 3 study testing 4CMenB vaccine in people with Gonorrhea and Sexually Transmitted Infection, run by Chinese University of Hong Kong at 1 site in Hong Kong.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 to 50 years, men onlyHealthy volunteers can take part
- Conditions the study is for
- Gonorrhea, Sexually Transmitted Infection
- What is being tested?
- 4CMenB vaccine
- Type of treatment
- Vaccines, Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 150 participants
- Where
- 1 siteHong Kong
- Study dates
- 4 May 2023to Dec 2026
- Phase
- Phase 3
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 50 years
- Men only
- Healthy volunteers accepted
- Adult
Who may be able to join
- 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
Who cannot join
- Contraindications to receive MenB vaccine
- Unable to give informed consent
Trial locations and contacts
1 site in 1 country.
About this study
Official title: 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.
Read more
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.
- Conditions
- Gonorrhea, Sexually Transmitted Infection
- Being tested
- 4CMenB vaccine, Placebo
- Medical subject headings
- Gonorrhea, Sexually Transmitted Diseases
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
4CMenB vaccineBiological
Also called Bexsero
Four-component MenB vaccine
PlaceboOther
0.9% Sodium Chloride Inj. B.P.
| Study group | Role | What they receive |
|---|---|---|
| Intervention | Experimental | Intramuscular injection of 2 doses of 0.5mL 4CMenB vaccine 1 month apart Receives: Biological: 4CMenB vaccine |
| Control | Placebo comparator | Intramuscular injection of 2 doses of 0.5mL placebo 1 month apart Receives: Other: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Comparison between incidence of NG between two groups
Difference in NG incidences in the two groups
Measured: Month 2 to Month 24
Secondary outcomes (2)
Changes in risk behaviours and networking pattern after vaccination
Frequency of sex networking, number of sex partners, and use of condoms
Measured: Month 2 to Month 24
Safety profile of the vaccine
Prevalence of adverse events
Measured: Month 2 to Month 24
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 Mar 2023
- Study start4 May 2023
- Primary completionSep 2026 (estimated)
- Study completionDec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for GonorrheaStudies of the same condition, open and under way.
- More trials run by Chinese University of Hong KongThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 3
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- 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 blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 150 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Chinese University of Hong Kong
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Tsz Ho Kwan, Chinese University of Hong Kong
- Investigators
- Tsz Ho Kwan, PhD, Principal investigator, Jockey Club School of Public Health and Primary Care
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05766904
- Sponsor's protocol ID
- 21200912
- Status last verified
- Mar 2026
- First submitted
- 1 Mar 2023
- Last updated
- 19 Mar 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 19 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Efficacy of a Meningococcal B Vaccine Against Neisseria Gonorrhoeae Infections Among Men Who Have Sex With Men: a Randomised-controlled Clinical Trial
- ClinicalTrials.gov ID
- NCT05766904
- Acronym / sponsor ID
- 21200912
- Conditions
- Gonorrhea, Sexually Transmitted Infection
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 150 participants (estimated)
- Lead sponsor
- Chinese University of Hong KongUniversity, hospital or other
- Study start
- 4 May 2023 (actual)
- Primary completion
- Sep 2026 (estimated)
- Study completion
- Dec 2026 (estimated)
- First posted
- 13 Mar 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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 design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
- 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.
| Arm | Type | Receives |
|---|---|---|
| Intervention | Experimental | Biological: 4CMenB vaccineIntramuscular injection of 2 doses of 0.5mL 4CMenB vaccine 1 month apart |
| Control | Placebo comparator | Other: PlaceboIntramuscular injection of 2 doses of 0.5mL placebo 1 month apart |
Who may qualify
- Ages
- 18 to 50 years
- Sex
- Male only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (8 listed)
- 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)
Key exclusion criteria (2 listed)
- Contraindications to receive MenB vaccine
- Unable to give informed consent
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| 4CMenB vaccineAlso: BexseroFour-component MenB vaccine | Biological | Intervention |
| Placebo0.9% Sodium Chloride Inj. B.P. | Other | Control |
Primary outcome
Comparison between incidence of NG between two groups
Time frame: Month 2 to Month 24
Difference in NG incidences in the two groups
2 secondary outcomes
Changes in risk behaviours and networking pattern after vaccination
Time frame: Month 2 to Month 24
Safety profile of the vaccine
Time frame: Month 2 to Month 24
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 19 Mar 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Tsz Ho Kwan, PhD principal investigator
Jockey Club School of Public Health and Primary Care
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing 4CMenB vaccine in people with Gonorrhea and Sexually Transmitted Infection, run by Chinese University of Hong Kong at 1 site in Hong Kong.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 8 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 19 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Hong Kong. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Comparison between incidence of NG between two groups (time frame: Month 2 to Month 24). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 19 Mar 2026; AzTrials last refreshed its copy on 26 Oct 2026.