A newly licensed preventive treatment for bronchiolitis has been shown to be 90 percent effective in preventing hospitalizations in infants this epidemic season in the United States, US health authorities announced Thursday, as quoted by AFP.

Acute bronchiolitis is a lung infection that often occurs in infants and children. This causes inflammation and congestion in the bronchioles, the smallest airways in the lung structure. In most cases, bronchiolitis is caused by a viral infection, and the winter months seem to be the most favorable for its occurrence.

The treatment being considered, nirsevimab, works by injecting an antibody designed to immunize infants against respiratory syncytial virus (RSV), which causes bronchiolitis.

Starting this summer, the United States recommended vaccination for infants younger than 8 months who are experiencing their first season of exposure to RSV if their mothers were not vaccinated during pregnancy.

The data, released Thursday by the Centers for Disease Control and Prevention (CDC), is the first to evaluate the effectiveness of treatment in the United States, where bronchiolitis is the leading cause of hospitalization among infants.

The study looked at 685 infants between October 2023 and February 2024 (according to health authorities, the entire epidemic season usually lasts from October to March).

“The results show that nirevimab was 90 percent effective in preventing virus-related hospitalizations in infants during the first bronchiolitis season,” the CDC wrote.

Most bronchiolitis is caused by respiratory syncytial virus, an infection that affects most children under the age of 2. Re-infection is possible, since the virus does not create permanent immunity. But not only the syncytial virus can cause bronchiolitis, there are cases provoked by the common cold or flu.