Actively Recruiting
Immunogenicity and Safety of COVID-19 Booster and Influenza Vaccine Co-administration and Timing in Immunocompromised Adults
Led by McGill University Health Centre/Research Institute of the McGill University Health Centre · Updated on 2026-03-10
660
Participants Needed
3
Research Sites
N/A
Total Duration
On this page
Sponsors
M
McGill University Health Centre/Research Institute of the McGill University Health Centre
Lead Sponsor
C
Centre hospitalier de l'Université de Montréal (CHUM)
Collaborating Sponsor
AI-Summary
What this Trial Is About
Researchers are evaluating ways to improve the immune response to COVID-19 booster and seasonal influenza vaccines in people living with immunocompromising conditions (PLIC), such as solid organ transplant recipients, people living with HIV, inflammatory bowel disease, and systemic autoimmune rheumatic diseases. This phase II randomized controlled trial aims to determine if co-administering the influenza vaccine with the COVID-19 booster is as effective as giving them sequentially, and whether more frequent COVID-19 boosters at 3-month intervals provide better long-term immunity compared to 6-month intervals. Participants will be assigned to one of four groups: receiving both COVID-19 booster and influenza vaccine on the same day with COVID-19 boosters every 3 months; receiving the COVID-19 booster at baseline and influenza vaccine one month later with boosters every 3 months; receiving both vaccines on the same day with boosters every 6 months; or receiving the COVID-19 booster at baseline and influenza vaccine one month later with boosters every 6 months. Vaccines used follow the National Advisory Committee on Immunization recommendations for immunocompromised patients. During the study, blood samples will be collected at multiple time points up to 12 months to measure immune responses, including antibody levels and T-cell activity. Researchers will monitor clinical events, therapies, vaccine side effects, quality of life, and economic impact. The main outcome is the median neutralization capacity against SARS-CoV-2 variants at specified intervals after vaccination, helping to inform optimal vaccine scheduling for this vulnerable population.
CONDITIONS
Brief Title
COVID-19 Booster and IIV Schedule in Immunocompromised Hosts
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Adults 18 years or older
- Have received at least three doses of the primary mRNA COVID-19 vaccine series
- Have one or more immunocompromising conditions including: a) Solid organ transplant at least 3 months ago with maintenance immunosuppression b) People living with HIV on antiretroviral therapy for at least 6 months meeting specific clinical or laboratory criteria c) Inflammatory bowel disease treated with immunosuppressive agents for at least 3 months d) Rheumatoid arthritis or systemic lupus erythematosus treated with immunosuppressive agents for at least 3 months
You will not qualify if you...
- Received seasonal influenza vaccine less than 6 months ago
- Received COVID-19 booster less than 3 months ago
- History of life-threatening reaction to any component of the influenza or COVID-19 vaccines
- History of Guillain-Barre syndrome or myocarditis within 6 weeks of previous influenza or COVID-19 vaccination
- Contraindication to intramuscular vaccines such as bleeding disorders or severe thrombocytopenia
- Receiving intravenous immunoglobulins
- Have underlying primary inborn errors of immunity
- Received chemotherapy such as cyclophosphamide less than 6 months ago
- Unable to provide informed consent
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 - 12 months
Participants receive COVID-19 booster doses and seasonal inactivated influenza vaccines according to their assigned schedule to assess immune response and safety.
Multiple visits including baseline, 1, 2, 4, 6, 7, 10, and 12 months after the first COVID-19 booster
Duration - Up to 12 months following initial booster dose
Participants are monitored over time to evaluate the durability of vaccine-induced immune responses and safety.
Visits coincide with vaccination follow-up schedule at 1, 2, 4, 6, 7, 10, and 12 months
Trial Site Locations
Total: 3 locations
1
Maisonneuve -Rosemont Installation
Montreal, Quebec, Canada, H1T2M4
Actively Recruiting
2
Centre hospitalier de l'Université de Montréal (CHUM)
Montreal, Quebec, Canada, H2X 0C1
Actively Recruiting
3
Research Institute of McGill University Health Centre
Montreal, Quebec, Canada, H4A 3J1
Actively Recruiting
Research Team
R
Ruth Sapir-Pichhadze, B.Med.Sc, MD, MSc, PhD, FRCPC
How is the study designed?
Study Type
INTERVENTIONAL
Masking
NONE
Allocation
RANDOMIZED
Model
FACTORIAL
Primary Purpose
PREVENTION
Number of Arms
4
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