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Virus Therapy

COVID-19 Booster + Flu Vaccine for Immunocompromised People (CO2I2 Trial)

Phase 2
Waitlist Available
Research Sponsored by McGill University Health Centre/Research Institute of the McGill University Health Centre
Eligibility Criteria Checklist
Specific guidelines that determine who can or cannot participate in a clinical trial
Must have
Adults (≥18 years)
Received the primary mRNA COVID-19 vaccine series (i.e., ≥3 doses)
Must not have
Contraindication to intramuscular vaccines such as bleeding disorder, severe thrombocytopenia, etc
Receiving intravenous immunoglobulins
Timeline
Screening 3 weeks
Treatment Varies
Follow Up baseline, 1, 2, 4, 6, 7, 10, and 12 months after the first study covid-19 booster
Awards & highlights
No Placebo-Only Group

Summary

"This trial aims to find the best way to boost the immune response in people with weakened immune systems. They want to see if getting the COVID-19 booster shot along with the flu vaccine at the same

Who is the study for?
This trial is for people with conditions like HIV, lupus, or rheumatoid arthritis that weaken their immune system. It's also for those who've had an organ transplant. Participants should be due for a COVID-19 booster and flu shot but can't join if they have certain health issues that aren't listed here.
What is being tested?
The study tests how well the body responds to different schedules of COVID-19 boosters and flu shots in immunocompromised individuals. It checks if giving both vaccines together works as well as spacing them out, and whether getting COVID-19 boosters every 3 months is better than every 6 months.
What are the potential side effects?
Possible side effects include typical reactions to vaccines such as soreness at the injection site, fever, fatigue, headache, muscle pain. The study will monitor any other adverse effects on participants' health.

Eligibility Criteria

Inclusion Criteria

You may be eligible if you check “Yes” for the criteria below
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I am 18 years old or older.
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I have received at least 3 doses of the mRNA COVID-19 vaccine.

Exclusion Criteria

You may be eligible for the trial if you check “No” for criteria below:
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I cannot receive vaccines by injection due to a bleeding disorder or very low platelet count.
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I am currently receiving IV immunoglobulin therapy.
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I have a genetic immune system disorder.
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I am unable to understand or sign the consent form.

Timeline

Screening ~ 3 weeks
Treatment ~ Varies
Follow Up ~baseline, 1, 2, 4, 6, 7, 10, and 12 months after the first study covid-19 booster
This trial's timeline: 3 weeks for screening, Varies for treatment, and baseline, 1, 2, 4, 6, 7, 10, and 12 months after the first study covid-19 booster for reporting.

Treatment Details

Study Objectives

Study objectives can provide a clearer picture of what you can expect from a treatment.
Primary study objectives
Median neutralization capacity against prevalent SARS-CoV-2 variant
Secondary study objectives
Anti-Spike and anti-Nucleocapsid concentrations
Hemagglutination inhibition (HI) response
IgA, and IgM antibody concentration
+3 more
Other study objectives
Adverse reactions to the vaccines
Death
Emergency room visits
+4 more

Awards & Highlights

No Placebo-Only Group
All patients enrolled in this study will receive some form of active treatment.

Trial Design

4Treatment groups
Experimental Treatment
Group I: Group 4Experimental Treatment2 Interventions
Covid-19 booster every 6 months and IIV at 1 month
Group II: Group 3Experimental Treatment2 Interventions
Covid-19 booster every 6 months and IIV at baseline
Group III: Group 2Experimental Treatment2 Interventions
Covid-19 booster every 3 months and IIV at 1 month
Group IV: Group 1Experimental Treatment2 Interventions
Covid-19 booster every 3 months and Inactivated influenza vaccine (IIV) at baseline

Find a Location

Who is running the clinical trial?

McGill University Health Centre/Research Institute of the McGill University Health CentreLead Sponsor
467 Previous Clinical Trials
165,883 Total Patients Enrolled
~440 spots leftby Dec 2025
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