2023-24 Nirsevimab Coverage (IIS), Children 0 to 19 months

Child Nirsevimab Coverage

• Nirsevimab coverage estimate numerators include the number of children who received at least one dose of nirsevimab from July 1, 2023, through the end of the reporting month, based on information that state, territorial, and local public health agencies report to CDC. Some jurisdictions may report data submitted by tribes. Estimates include children who are deceased but received nirsevimab during the current season. Children receiving doses are attributed to the jurisdiction in which the child resides unless noted otherwise. Quality and completeness of data may vary across jurisdictions. Nirsevimab coverage denominators are obtained from 2020 U.S. Census Bureau population estimates.
• Monthly estimates shown are cumulative, reflecting all children who received nirsevimab from July 2023 through the end of the reporting month. Cumulative estimates include any historical data reported since the previous submission. National estimates are not presented since not all U.S. jurisdictions are currently reporting their IIS data to CDC. Jurisdictions reporting data to CDC include U.S. states, some localities, and territories.
• Because IIS data are intended to capture all doses administered within a jurisdiction rather than a sample, standard errors were not calculated.
• Laws and policies regarding the submission of these data to an IIS vary by state, which may impact the completeness of coverage reflected for a jurisdiction.
• Coverage estimates based on IIS data are expected to differ from National Immunization Survey (NIS) estimates for children. NIS estimates are based on a sample that may not be representative after survey weighting and vaccination status is determined by survey respondent rather than vaccine records or administrations. Quality and completeness of IIS data may vary across jurisdictions. In general, NIS estimates tend to overestimate coverage due to overreporting and IIS estimates may underestimate coverage due to incompleteness of data in certain jurisdictions.
• The NIS and IIS estimates are based on different groups of children recommended to receive nirsevimab. The IIS estimates include only those children recommended as of September 30, 2023, and excludes children who would become eligible on or after October 1, 2023 (e.g., children born or turning age 19 months in October 2023 or later). In NIS, nirsevimab receipt by the baby is only asked of female survey respondents aged 18-49 years with an infant <8 months in the household; this would include children born after September 30, 2023, but would not include children ages 8-19 months at increased risk for severe RSV disease. NIS estimates may not be representative of households with infants <8 months without a female 18-49 years in the household, for which the survey respondent was a female age 50 years or more, or had a male survey respondent aged 18 or more years.
• IIS coverage estimates reported on jurisdictions' dashboards may use different criteria for numerators and denominators (e.g. jurisdictions may use IIS-based denominator instead of census population) and thus IIS estimates may differ from those reported on CDC's Weekly RSV Vaccination dashboard.
• Figure 7A. Monthly Cumulative Number and Percent of Children <20 Months Who Received Nirsevimab*^,† by Age Group and Jurisdiction, United States. Data Source: U.S. Jurisdiction Immunization Information Systems (IIS). Data are current through March 31, 2024.
• Figure 7B. Monthly Cumulative Number and Percent of Children <20 Months Who Received Nirsevimab*^,† by Age Group and Jurisdiction, United States. Data Source: U.S. Jurisdiction Immunization Information Systems (IIS). Data are current through March 31, 2024.