Evaluating How Well Perinatal RSV Immunoprophylaxis Protects Infants Under 12 Months in Real-World Settings

What this Trial Is About

Researchers are evaluating the real-world effectiveness of perinatal RSV immunoprophylaxis in infants up to 12 months old. The study aims to understand how well these vaccines work in routine clinical practice, including their overall effectiveness, duration of immunity, effectiveness against new RSV strains, and variations in effectiveness by age. This large-scale case-control study uses active surveillance to identify infants with respiratory illness and confirm RSV infection through molecular tests. The study includes infants who received immunoprophylaxis such as maternal vaccines or the drug Nirsevimab, comparing those who tested positive for RSV cases with healthy controls matched by birth date, sex, and type of immunization, as well as with controls who have respiratory illness but test negative for RSV. Data will be gathered from health records, interviews, immunization registries, and surveys. The study also involves genetic analysis of RSV viruses and detailed immune response studies using blood samples from a subset of infants. Participants will be infants aged 12 months or younger residing in Connecticut who seek care for acute respiratory illness. Investigators will collect clinical data, laboratory test results, and immune response information over up to five years. The main outcomes measured include the overall effectiveness of RSV immunoprophylaxis and its effectiveness against different viral strains, along with immune system dynamics. Safety monitoring and follow-up will continue during this time to provide a comprehensive assessment of vaccine performance in everyday clinical use.

Real-World Effectiveness of Perinatal RSV Immunoprophylaxis