Context:

The infant mortality rate in the United States decreased in 2024 after two years of stagnation at a late-pandemic plateau, dropping to about 5.5 deaths per 1,000 live births from 5.6 per 1,000 in previous years. Experts partially attribute this decline to a vaccination campaign against RSV (respiratory syncytial virus), which can cause severe cold-like symptoms dangerous for infants. The introduction of a lab-made antibody shot for infants and an RSV vaccine for pregnant women between 32 and 36 weeks of gestation likely contributed to the reduction in infant hospitalizations during the 2024-25 respiratory virus season by over 40% compared to past averages. Despite these improvements, the U.S. infant mortality rate remains higher than in other high-income countries, often linked to factors such as poverty and inadequate prenatal care. Further investigation is needed to understand other contributing factors to the decline, as improvements were noted in infants who were at least one month old, indicating reduced deaths from various causes like accidents, homicides, or SIDS.

Dive Deeper:

• The U.S. infant mortality rate saw a decline from 5.6 to 5.5 deaths per 1,000 live births in 2024, with provisional data suggesting little change expected in final numbers. This marks a significant improvement after two years of increased rates due to a rebound in RSV and flu infections post-pandemic.

• RSV, a virus causing severe cold-like symptoms in infants, became a focus for health officials who introduced a lab-made antibody shot for infants and a vaccine for pregnant women, potentially explaining the lower mortality rate and reduced hospitalizations during the 2024-25 respiratory virus season.

• The 2024 decline in infant mortality is a positive development amid the U.S.'s historically higher rates compared to other high-income countries, where factors like poverty and inadequate prenatal care have been major contributors.

• While the U.S. has generally seen improvements in infant mortality over the decades due to medical advances, the 2022 and 2023 rates marked the first significant jump in nearly twenty years, linked to the return of RSV and flu infections after pandemic-related precautions were lifted.

• Dr. Amanda Williams from the March of Dimes highlighted that much of the 2024 improvement was observed in infants older than one month, indicating that fewer deaths from causes such as accidents, homicides, or SIDS might also play a role, alongside the reduced impact of RSV.