Actively Recruiting
An Investigator-initiated Study to Investigate Gender and Sex Differences in Immune Responses to Meningococcal Serogroup B Vaccination in Healthy Transgender and Cisgender Adults Aged 18 to 50 Years
Led by University Ghent · Updated on 2026-01-20
250
Participants Needed
1
Research Sites
21 weeks
Total Duration
On this page
Sponsors
U
University Ghent
Lead Sponsor
U
University Hospital, Ghent
Collaborating Sponsor
AI-Summary
What this Trial Is About
Researchers are investigating how sex and gender differences affect immune responses to vaccines by studying transgender and cisgender individuals. This study focuses on the immune reactions to the four-component meningococcal serogroup B (4CMenB; Bexsero®) vaccine. It aims to understand how hormonal changes in transgender people, who retain their chromosomal sex but undergo gender-affirming hormone therapy, influence both humoral and cellular immune responses compared to cisgender individuals. Participants will receive two doses of the 4CMenB vaccine via intramuscular injections in the non-dominant upper arm, spaced one month apart. The study includes four groups of 30 individuals each: cisgender men, cisgender women, transgender women, and transgender men. Transgender participants must have been on stable gender-affirming hormone therapy for at least six months. The vaccination process and immune response evaluation will take place over a set period following the first dose. During the study, participants will undergo medical evaluations including medical history and physical exams to confirm general health and eligibility. Immune responses, including antibody production and T cell activity, will be measured from the first vaccination to two months after the primary vaccination. The study monitors safety and compliance, requiring participants to attend follow-up visits and adhere to study procedures. The total participation duration covers vaccination and subsequent immune response assessment over several months.
CONDITIONS
Brief Title
Investigating Gender and Sex Differences in Immune Responses Through Vaccination of Transgender and Cisgender Persons
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Signed informed consent form before any study activities.
- Age between 18 and 50 years at the time of first study intervention.
- Good general health based on medical history and physical exam.
- Body mass index (BMI) between 18.5 and 35 kg/m2 at screening.
- Not pregnant, breastfeeding, or planning pregnancy during the study.
- Transgender individuals must be on stable gender-affirming hormone therapy for at least 6 months with lab confirmation.
- Negative urine pregnancy test at each vaccination visit for persons capable of becoming pregnant.
- Willing and able to comply with study procedures and follow-up visits.
You will not qualify if you...
- Current or past confirmed or suspected disease caused by N. meningitidis or N. gonorrhoeae.
- Close contact or exposure to someone with confirmed meningococcal infection.
- Transgender persons in diagnostic phase without hormone therapy or on hormone-suppressing treatments.
- Current or past infection with hepatitis B, hepatitis C, or HIV.
- History or presence of immune-suppressive or immune-deficient conditions.
- Severe allergic reactions to vaccine components or related medical products.
- Conditions contraindicating intramuscular injections or blood draws.
- History of absence or removal of the spleen.
- Active or recent malignancy affecting immune response or safety.
- History of idiopathic urticaria within the past year.
- Pregnancy, breastfeeding, or planning pregnancy; certain infertility or menopause conditions.
- Other clinical conditions affecting safety or study compliance, including heavy smoking, substance abuse, unstable psychiatric conditions.
- Recent blood donation or vaccination with group B meningococcal vaccine.
- Recent or planned live-attenuated or inactivated vaccines interfering with study vaccine.
- Participation in other clinical studies or investigational treatments recently or planned.
- Recent receipt or planned receipt of blood products or immunoglobulins.
- Recent or planned use of immunosuppressive drugs excluding certain topical or inhaled forms.
- Use of specific hormonal contraceptives inhibiting ovulation in persons capable of becoming pregnant.
- Current tuberculosis treatment or prophylaxis.
- Any other medical condition that may affect study results or participant safety.
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
Your Study Journey
Duration - 2 to 4 weeks
Participants are screened for eligibility to participate in the trial.
1 visit (in-person)
Duration - 1 month
Participants receive two intramuscular injections of the 4CMenB vaccine, administered one month apart.
2 vaccination visits (in-person)
Duration - 2 months
Participants are monitored for immune responses and safety for two months after the first vaccination.
Multiple follow-up visits
Trial Site Locations
Total: 1 location
1
CEVAC, University Hospital Ghent, Belgium
Ghent, Belgium, 9000
Actively Recruiting
Research Team
P
Prof. Dr. Isabel Leroux-Roels, PhD, MD
D
Dr. Valentino D'Onofrio, PhD
How is the study designed?
Study Type
INTERVENTIONAL
Masking
NONE
Allocation
NON_RANDOMIZED
Model
PARALLEL
Primary Purpose
BASIC_SCIENCE
Number of Arms
4
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