RSV immunization uptake among infants and pregnant persons - Wisconsin, October 1, 2023-March 31, 2024

Area of Science:

• Pediatrics
• Immunology
• Public Health

Background:

• Respiratory syncytial virus (RSV) is a major cause of infant hospitalizations in the U.S.
• New preventive tools include the maternal RSVpreF vaccine and nirsevimab, a long-acting monoclonal antibody.
• Evaluating the uptake of these new RSV interventions is critical for public health strategies.

Purpose of the Study:

• To assess the immunization coverage of the maternal RSVpreF vaccine and nirsevimab among infants born in the 2023-24 season.
• To determine the overall infant protection rate against RSV based on the uptake of these new preventive products.
• To identify potential barriers and areas for improvement in accessing and administering RSVpreventive measures.

Main Methods:

• Utilized data from the Wisconsin Immunization Registry and Office of Vital Records.
• Examined immunization records for infants born during the 2023-24 RSV season.
• Analyzed the uptake of nirsevimab and the maternal RSVpreF vaccine, including dual product administration.

Main Results:

• 18.2% of infants received nirsevimab, and 17.2% of birthing persons received the maternal RSVpreF vaccine.
• Only 0.8% of parent-infant dyads received both preventive products.
• Overall infant protection against RSV was achieved in 36.2% of the studied population.

Conclusions:

• Current uptake rates for both maternal RSVpreF vaccine and nirsevimab are suboptimal.
• Significant improvements in access, awareness, and administration are needed to increase infant protection against RSV.
• Equitable distribution and timely administration of these new RSVpreventive products are essential for reducing disease burden.