COVID-19-Associated Hospitalizations and Maternal Vaccination Among Infants Aged <6 Months - COVID-NET, 12 States, October 2022-April 2024.

Infants aged <6 months are at increased risk for severe COVID-19 disease but are not yet eligible for COVID-19 vaccination; these children depend upon transplacental transfer of maternal antibody, either from vaccination or infection, for protection. COVID-19-Associated Hospitalization Surveillance Network (COVID-NET) data were analyzed to estimate COVID-19-associated hospitalization rates and identify demographic and clinical characteristics and maternal vaccination status of infants aged <6 months hospitalized with laboratory-confirmed COVID-19. During October 2022-April 2024, COVID-NET identified 1,470 COVID-19-associated hospitalizations among infants aged <6 months. COVID-19-associated hospitalization rates among young infants were higher than rates among any other age group, except adults aged ≥75 years, and are comparable to rates among adults aged 65-74 years. The percentage of hospitalized infants whose mothers had been vaccinated during pregnancy was 18% during October 2022-September 2023 and decreased to <5% during October 2023-April 2024. Severe outcomes among infants hospitalized with COVID-19 occurred frequently: excluding newborns hospitalized at birth, approximately one in five young infants hospitalized with COVID-19 required admission to an intensive care unit, nearly one in 20 required mechanical ventilation, and nine infants died during their COVID-19-associated hospitalization. To help protect pregnant persons and infants too young to be vaccinated, prevention for these groups should focus on ensuring that pregnant persons receive recommended COVID-19 vaccines.
Competing Interests: All authors have completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. Andrea George reports grants from the Council of State and Territorial Epidemiologists during the study. Lauren Leegwater reports grants from the Michigan Department of Health and Human Services during the study. No other potential conflicts of interest were disclosed.