May 9 (Reuters) - Infant hospitalizations due to

respiratory syncytial virus (RSV) infections in the United

States dropped as much as 43% last year compared to previous

years, following the widespread availability of preventative

shots, federal data showed.

The U.S. Centers for Disease Control and Prevention in a

report on Thursday said that hospitalizations related to RSV

decreased by 28% and 43% across two large national databases,

compared to pooled rates from 2018-2020.

Years from 2020 to 2023 were excluded from the study because

the COVID-19 pandemic led to unusual RSV seasonality and

circulation, the study authors said.

WHY IT'S IMPORTANT

The 2024-2025 season marked the first period of widespread

availability of preventive shots against RSV, a virus that often

results in cold-like symptoms but is a major cause of severe

infection and death in infants and older adults.

Separately, CDC data showed a drop in the infant mortality

rate in 2024, compared to the previous year.

Pfizer's ( PFE ) maternal vaccine, sold as Abrysvo, and

Sanofi and AstraZeneca's ( AZN ) antibody shot,

Beyfortus, are available in the United States to prevent RSV

infection in infants.

BY THE NUMBERS

The largest estimated reductions in hospitalization rates

occurred among infants aged up to 2 months, the CDC said.

The infant mortality rate in the United States, defined as

the number of deaths of children under one year of age per 1,000

live births, dropped to 5.49 in 2024, down from 5.63 a year

earlier, CDC data showed.

CONTEXT

The data suggest that the most severe RSV disease among

infants up to seven months old is preventable, the CDC said,

adding that it is important to protect infants, ideally within

their first week of life, especially those born during the RSV

season.