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

Respiratory syncytial virus (RSV) is the leading cause of hospitalizations among infants in the United States. New strategies to prevent RSV among infants and high-risk young children include the maternal RSVpreF vaccine (Abrysvo, Pfizer Inc.) and nirsevimab (Beyfortus, Sanofi and AstraZeneca), a long-acting monoclonal antibody. We examined immunization coverage among infants born during the 2023-24 RSV season and pregnant persons utilizing data from the Wisconsin Immunization Registry and Office of Vital Records to evaluate uptake of both products and overall infant protection against RSV. 5056 (18.2 %) infants received nirsevimab and 4767 (17.2 %) persons who gave birth during this timeframe received the maternal RSVpreF vaccine; 0.8 % of parent-infant dyads received both products. Overall, 36.2 % of infants were protected from RSV. These findings suggest that improved efforts on several fronts are needed to ensure equitable and timely access to both RSV products while also increasing the number of infants protected against RSV.