Actively Recruiting
Concurrent Versus Sequential Administration of Tdap and RSV Vaccines in Pregnancy - A Pilot Feasibility Trial
Led by Canadian Immunization Research Network · Updated on 2026-03-12
60
Participants Needed
4
Research Sites
74 weeks
Total Duration
On this page
Sponsors
C
Canadian Immunization Research Network
Lead Sponsor
O
Ottawa Hospital Research Institute
Collaborating Sponsor
AI-Summary
What this Trial Is About
This research aims to find out if giving the RSV vaccine and the Tdap vaccine to pregnant individuals at the same visit or at separate visits is more effective and safe. The study focuses on healthy pregnant people between 18 and 49 years old, assessing how well these vaccines work together during pregnancy and the safety of receiving them either concurrently or sequentially. It is a Phase 4 randomized controlled trial led by the Canadian Immunization Research Network. Participants are randomly assigned to one of two groups: Group 1 receives both the Tdap and RSV vaccines during the same visit, while Group 2 receives the vaccines at different visits. Vaccines are given following official guidelines, with participants asked to look away during administration to maintain blinding. The main study includes four visits involving blood collection and vaccine administration, while an optional exploratory part includes six more visits for breast milk and infant blood sample collection to measure antibody levels over time. Throughout the study, participants provide blood samples, and for infants, cord blood and blood samples are collected after birth. Breast milk samples are also taken at several points postpartum. Participants keep a diary of symptoms to help monitor safety and immune responses. The study measures rates of adverse events, immune responses to the vaccines, and protocol compliance, with follow-up visits continuing up to about 19 months after birth for some measures. The total study participation includes up to ten visits depending on optional participation.
CONDITIONS
Brief Title
Concurrent Versus Sequential Administration of Tdap and RSV Vaccines in Pregnancy
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Healthy pregnant individuals with a single pregnancy aged 18 to 49 years
- Pregnancy between 28 weeks and 29 weeks plus 6 days gestational age at screening and enrollment
- Able to follow study procedures needed for the main study objectives
- Informed consent signed before any study-specific procedures
You will not qualify if you...
- Receipt of any RSV vaccine previously
- Receipt of immunoglobulins (except Rho D) within 1 year before vaccination
- Receipt of pertussis vaccine within 2 years before vaccination
- Documented pertussis infection within 2 years before vaccination
- Receipt of blood transfusion products within 6 months before vaccination
- Immunologic disorders or immunosuppression
- Conditions that interfere with compliance or prenatal care, such as behavioral or cognitive impairments
- Preconception diabetes mellitus
- Preconception chronic hypertension
- Congenital anomalies detected by ultrasound
- Hepatitis B or C infection, or untreated syphilis
- Contraindications to Tdap vaccine (BOOSTRIX) including hypersensitivity or neurological complications
- Contraindications to RSVpreF vaccine (ABRYSVO) including hypersensitivity
- Pregnancy complications that increase risk of preterm delivery, including gestational hypertension, pre-eclampsia, uncontrolled gestational diabetes, fetal growth restriction, placenta anomalies, polyhydramnios, oligohydramnios, short uterine cervix, or acute illness with fever within 24 hours before vaccination (with possible delayed vaccination)
AI-Screening
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Your Study Journey
Duration - 2 to 4 weeks
Participants are screened for eligibility to participate in the trial.
1 visit (in-person)
Duration - Up to 12 weeks
Participants receive Tdap and RSV vaccines either concurrently or sequentially as per their assigned group, with blinding maintained by asking participants to look away during vaccine administration.
4 visits (in-person) including vaccination and follow-up assessments
Duration - Up to 14 weeks after first vaccination
Participants are monitored for safety and immunogenicity outcomes up to 14 weeks after the first vaccination.
Additional visits as needed for safety monitoring
Trial Site Locations
Total: 4 locations
1
Vaccine Evaluation Center
Vancouver, British Columbia, Canada
Actively Recruiting
2
Canadian Center for Vaccinology
Halifax, Nova Scotia, Canada
Actively Recruiting
3
The Ottawa Hospital Research Institute
Ottawa, Ontario, Canada
Actively Recruiting
4
Centre hospitalier universitaire Ste-Justine
Montreal, Quebec, Canada
Actively Recruiting
Research Team
B
Bahaa Abu-Raya, M.D, PhD
C
CTN CIRN Central Inbox
How is the study designed?
Study Type
INTERVENTIONAL
Masking
QUADRUPLE
Allocation
RANDOMIZED
Model
CROSSOVER
Primary Purpose
PREVENTION
Number of Arms
2
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