Studies demonstrate safety and effectiveness of RSV prevention drugs in children

Two studies published in Pediatrics To demonstrate the safety and efficacy of the preventive drug nirsevimab against respiratory syncytial virus (RSV) in children and infants.

Nirsevimab (Beyfortus) is a long-acting monoclonal antibody. Currently, the Centers for Disease Control and Prevention in the United States recommends one dose of nirsevimab for infants younger than 8 months who were born shortly before or are experiencing the first RSV season (usually fall through spring) if their mother was not vaccinated against RSV during pregnancy.

Some children, including those with cystic fibrosis or chronic lung prematurity, are recommended to continue receiving the medicine during their second RSV season (8 to 19 months of age).

No serious adverse events

The first study In the open-label Phase 2 MUSIC trial, researchers tested the drug in 100 immunocompromised American children aged 24 months or younger. Among the children were 33 with primary immunodeficiency, 16 with a previous transplant and 8 with HIV infection. Also included were 29 children who were treated with high-dose systemic corticosteroids, 20 with immunosuppressive chemotherapy and 15 with other immunosuppressive therapies.

The children were followed for 360 days. During the study, three children died from a lower respiratory tract infection (LRTI) not caused by RSV. Eight treatment-related side effects were recorded in six children, but none of them were classified as serious.

The authors found that mean serum nirsevimab concentrations in study participants were lower at day 151 than in healthy infant participants. However, no cases of RSV LRTI occurred up to day 151, the observation period during which efficacy was demonstrated.

“In immunocompromised children aged ≤24 months, nirsevimab was well tolerated, there were no safety concerns, and serum concentrations were supportive of efficacy.“ the authors concluded.

Hospital admissions in Spain down 63%

Last year, Spain was one of the first countries to introduce universal RSV prevention through a single dose of nirsevimab for newborns up to 6 months of age. second study In Pediatrics shows that the policy was tied to a reduction in RSV hospitalizations by more than half.

The guideline resulted in a 63.1% reduction in hospital admissions for acute bronchiolitis (95% confidence interval [CI]60.9% to 65.2%) and a reduction in pediatric intensive care unit admissions by 63.1% (95% CI, 58.1% to 67.9%).

The study compared RSV hospital admission rates and outcomes in 15 Spanish hospitals during the 2023–2024 season (November to January) with the 2018 to 2023 seasons.

Acute bronchiolitis may become a rare disease in the near future and the significant health burden of RSV in infants could be greatly reduced.

“Although we had limited data on less stringent implementation strategies, an approach that includes an extended catch-up phase was found to be the most effective, although cost-effectiveness must also be taken into account.“ the authors concluded. “With proper application of immunization strategies, acute bronchiolitis could become a rare disease in the near future and the significant health burden of RSV in infants could be greatly reduced.“

Wastewater detection of RSV, influenza and COVID viruses

Finally, researchers in Oregon discovered a strong correlation between viral wastewater concentrations and positive respiratory tests in the population for influenza viruses, RSV and SARS-CoV-2, the virus that causes COVID-19. to a new study In Emerging infectious diseases.

The researchers compared weekly wastewater concentrations of SARS-CoV-2, influenza and RSV with patients' positive test results from September 6, 2020, to May 11, 2023. The study included 48 wastewater treatment plants serving 62.3% of Oregon's population.

Overall, there were strong, positive correlations for SARS-CoV-2, influenza virus and RSV.

“The strength of the observed association suggests that wastewater surveillance serves as an indicator of community transmission of these pathogens.“ the authors concluded. “Wastewater data are not influenced by health-seeking behavior or testing bias, can be analyzed in near real-time using collected community samples, and can be localized down to the sewer level to inform local public health decisions.“