Revaccination with RSV vaccine during subsequent pregnancies

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This study evaluates the safety and tolerability of a second dose of the RSVpreF vaccine in pregnant women who previously received the vaccine. It includes two cohorts of pregnant participants: one receiving the second dose and another randomly assigned to receive either the vaccine or a placebo. Additionally, non-pregnant participants will have their blood analyzed to assess the duration of immunity from a prior vaccination. The study aims to monitor the immune response and safety for both mothers and their infants over a six-month period post-birth.

Why it matters

Who can join: the full rules

Pregnant Participants-Cohort 1 and Cohort 2 Key Inclusion Criteria

* Women aged 18 to 49 who are pregnant, between 24 and 36 weeks along, and expecting one baby without known risks for complications can participate.
* Had the RSVpreF or Abrysvo vaccine during a previous pregnancy.
* Had an ultrasound scan at 18 weeks or later during their current pregnancy, with no major fetal problems detected.
* Based on their medical history, physical check-up, and the doctor's judgment, they are found suitable to join the study.
* Agrees to let their baby take part in the study and gives their permission.
* Able to sign a consent form, agreeing to follow the rules and conditions of the study.

Key Exclusion Criteria

* Received any approved or experimental RSV vaccine since their previous pregnancy.
* Has a pre-pregnancy body mass index (BMI) over 40 kg/m2.
* History of a severe bad reaction to a vaccine or a serious allergic reaction (like anaphylaxis) to any ingredient in the study vaccine or a similar vaccine.
* Current pregnancy problems or issues at the time of giving consent.
* Previous pregnancy issues or problems at the time of giving consent.
* Women who are breastfeeding at the time of enrollment

Infant Participants

* Proof that the parent(s) or legal guardian(s) has signed and dated a consent form.
* Parent(s) or legal guardian(s) must agree to attend scheduled visits and follow the study plan, including laboratory tests and other procedures.

Nonpregnant Participants-Cohort 3 Key Inclusion Criteria

* Have already received one dose of the RSVpreF vaccine during their previous pregnancy as part of the Pfizer clinical trial, and the results from that time can be used for this study.
* Able to sign a consent form, agreeing to follow the rules and requirements of the study.

Key Exclusion Criteria

* Received any approved or experimental RSV vaccine after participating in the Pfizer clinical trial.
* Taking part in other studies with new drugs within 28 days before giving consent or during the study period.

Where it's running

• Center for Research in Women's Health
  Birmingham, Alabama, United States Recruiting
• Children's of Alabama
  Birmingham, Alabama, United States Recruiting
• University of Alabama at Birmingham - School of Medicine
  Birmingham, Alabama, United States Recruiting
• University of Alabama at Birmingham Women & Infants Center
  Birmingham, Alabama, United States Recruiting
• USA Health Children's and Women's Hospital
  Mobile, Alabama, United States Recruiting
• USA Health Strada Patient Care Center
  Mobile, Alabama, United States Recruiting

+47 more sites. See ClinicalTrials.gov for the full list.

Study contacts

• Study coordinator: Pfizer CT.gov Call Center
• Email: ClinicalTrials.gov_Inquiries@pfizer.com
• Phone: 1-800-718-1021

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

• Zelicapavir for RSV infection in young children

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  Recruiting at 5 sites Phase 1 Clover Biopharmaceuticals, Ltd · Phoenix, Arizona and 4 other locations · NCT06843317

• Vaccination against RSV in patients with weakened immune systems

  This study tests if giving two doses of the RSV vaccine to patients with weakened immune systems helps them better fight off RSV infections compared to the standard one dose given to healthy older adults.

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• Evaluating the effectiveness of RSV vaccines in real-world settings

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• Measuring how RSV affects young children seen in clinics and hospitals

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  Recruiting Association Clinique Thérapeutique Infantile du val de Marne · Créteil · NCT04743609

How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.