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NCT06647654

Impact and Effectiveness of ABRYSVO® Vaccination During Pregnancy

Sponsor: Pfizer

View on ClinicalTrials.gov

Summary

This study will be conducted in collaboration with a research network of independent hospital sites to evaluate the vaccine effectiveness (VE) and impact of ABRYSVO vaccination during pregnancy in a real-world population over multiple seasons, which began in 2024 across Argentina and beginning in 2025 in Uruguay. We will use three retrospective design approaches in this study: (i) a test negative design (TND) to evaluate real-world VE of maternal ABRYSVO against RSV-associated outcomes in infants; (ii) a descriptive cohort design to evaluate the clinical evolution of infants hospitalized with RSV-positive lower respiratory tract disease (LRTD); and (iii) an ecologic before-and-after design to evaluate the impact of ABRYSVO vaccination during pregnancy on infant RSV-associated and all-cause respiratory outcomes.

Official title: Real World Impact and Effectiveness of ABRYSVO® Vaccination During Pregnancy Against RSV Illness in Infants

Key Details

Gender

All

Age Range

0 Years - 24 Months

Study Type

OBSERVATIONAL

Enrollment

Start Date

2024-08-26

Completion Date

2026-10-01

Last Updated

2025-10-02

Healthy Volunteers

Conditions

Respiratory Syncytial Virus Respiratory Tract Diseases

Interventions

BIOLOGICAL

ABRYSVO

Test Negative Design: This is a non-interventional retrospective study; therefore, ABSYRVO vaccine has already been administered according to the standard of care. ABRYSVO is a bivalent RSV prefusion F protein-based vaccine (RSVpreF) composed of two prefusion F proteins to protect against both RSV-A and RSV-B. Ecologic Before-and-After Design: This is an ecologic before-and-after study using aggregated data; as such, the 'exposure' of interest is time before ABRYSVO program implementation (i.e., five historical pre-ABRYSVO RSV seasons) and time after ABRYSVO implementation (i.e., post-ABRYSVO RSV seasons: 2024-2026).

Test Negative Design Inclusion Criteria: 1. Infants ≤9 months (≤270 days) of age on the index date. 2. Index date within the time period for data collection (approximately 01 April to 30 September in 2024, 2025, or 2026). 3. Infants born at 32 weeks of gestational age or greater. 4. Hospitalized for at least 24 hours with LRTD (symptoms related to LRTD might be absent at the time of admission but if they develop within the first 24 hours of hospitalization, the criteria for LTRD will be considered met), and specimen collected for RSV within 10 days prior to hospital admission through 3 days after a hospital admission through SOC testing. 5. Infant date of birth 14 days or more after start of the first seasonal ABRYSVO vaccination campaign, to ensure potential to have been born to an ABRYSVO-vaccinated individual. 6. Infant born to individuals who were expected (based on estimated date of delivery) to reach the indicated ABRYSVO vaccination window (320/7 to 366/7 weeks' gestation) during a local ABRYSVO vaccination season. Test Negative Design Exclusion Criteria: 1. Received any licensed or investigational RSV preventive product (e.g., Palivizumab, Nirsevimab, active RSV vaccine) since birth. 2. Received ≥1 blood transfusion or other blood products containing antibody (e.g., fresh frozen plasma) since birth. 3. Born to individual who received any other licensed or investigational RSV vaccine during pregnancy. 4. Born to individual for whom ABRYSVO vaccination status cannot be confirmed in available data sources. 5. Infants with LRTD that require hospitalization for reasons other than clinical criteria (e.g., for social reasons, other medical condition in an infant with LRTD without hospitalization criteria). Cohort Design Inclusion Criteria: 1\. RSV positive cases ≤9 months of age from the TND study. Cohort Design Exclusion Criteria: None. Ecologic Before-and-After Design Inclusion Criteria: 1. Infants and children ≤24 months of age on the index date. 2. Index date during the calendar years for data collection (pre- or post-ABRYSVO program implementation. 3. Meets ≥1 outcome definition during the time period for data collection. Ecologic Before-and-After Design Exclusion Criteria: None.

Locations (1)

Pfizer

Buenos Aires, Argentina