Evaluating COVID-19 booster effects in pregnant and breastfeeding women

Serological and Functional Impact of COVID-19 Vaccination on the Maternal Fetal Unit and Infant Immunity

Thomas Jefferson University · NCT05543993

This study tests how a COVID-19 booster shot affects the immunity of pregnant and breastfeeding women and their babies against different COVID-19 variants.

Quick facts

Study typeObservational
Enrollment200 (estimated)
Ages13 Years to 55 Years
SexFemale
SponsorThomas Jefferson University (other)
Locations1 site (Philadelphia, Pennsylvania)
Trial IDNCT05543993 on ClinicalTrials.gov

What this trial studies

This observational study aims to assess the impact of COVID-19 mRNA booster vaccination on maternal and infant immunity against COVID-19 variants. It will enroll 100 pregnant women and 100 breastfeeding women who have received the booster, following them longitudinally for three months postpartum or three months post-enrollment for breastfeeding participants. Maternal blood, cord blood at delivery, breast milk, and infant samples will be collected to evaluate immune responses over time.

Who should consider this trial

Good fit: Ideal candidates for this study are pregnant women or breastfeeding women who have received the mRNA bivalent COVID-19 booster.

Not a fit: Patients with multifetal gestation or those unable to provide consent may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could enhance understanding of how COVID-19 vaccination affects immunity in mothers and infants, potentially leading to improved health outcomes.

How similar studies have performed: Other studies have explored the effects of COVID-19 vaccination during pregnancy and lactation, indicating a growing body of evidence in this area.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Singleton gestation
* Received mRNA bivalent COVID-19 booster during 1) pregnancy or 2) breastfeeding

Exclusion Criteria:

* Multifetal gestation
* Unable to provide consent

Where this trial is running

Philadelphia, Pennsylvania

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: COVID-19, vaccine, COVID-19 vaccine, booster, pregnancy, breastfeeding, immunity

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.