# Changes in pediatric primary care contacts: has the RSV-immunization modified the age-related access?

## TL;DR

This study found that the RSV immunization nirsevimab reduced bronchiolitis in infants and changed the pattern of pediatric care visits in Italy.

## Contribution

The study provides empirical evidence on how RSV immunization affects pediatric care utilization and disease burden in real-world settings.

## Key findings

- The introduction of nirsevimab led to a significant decline in bronchiolitis-related contacts among infants under one year.
- The seasonal peak of bronchiolitis was delayed in 2025 compared to previous years.
- The difference in primary care contacts between 1-year-olds and 2-year-olds decreased after nirsevimab introduction.

## Abstract

Primary care is essential during children’s development, especially in the first years of life. Contacts with the Family Pediatricians (FP) always presented with seasonality, peaking in infants and toddlers. In Italy, nirsevimab was widely introduced in November 2024, potentially influencing the pattern of pediatric care utilization. This study aimed to evaluate temporal changes in FP contacts and the burden of bronchiolitis following nirsevimab introduction.

A retrospective observational study has been conducted within Pedianet, an Italian primary-care network of FPs. Children residing in the Veneto region under five years of age and active between September 2022 and 2025 were included. All FP contacts were considered, identifying bronchiolitis-related visits and immunization ones. Age-specific incidence rates (IR) expressed in 100 person-months with 95% confidence intervals (CI) were calculated.

A total of 25,399 children (median follow-up: 20.99 months) were included. Overall, 71.68 (95%CI:71.46–71.91) contacts per 100 person-months were recorded, showing clear seasonality with decreasing incidence while increasing age. After excluding immunization contacts, the difference in IRs between children in their first and second year of life was smaller in 2024/2025 than in 2023/2024, particularly in November (1-year:88.96 [95%CI:85.78–92.14] and 2-year:84.68 [95%CI:81.40–87.95] compared with 119.3 [95%CI:115.47–123.12] and 94.19 [95%CI:90.72–97.66]). Bronchiolitis burden among infants < 1 year declined from 6.58 (95%CI:5.70–7.47) to 1.24 (95%CI:0.87–1.62) contacts per 100 person-months in January 2024 and 2025, respectively, with a delayed seasonal peak in February 2025 (IR = 2.00, 95%CI:1.50–2.50).

Following nirsevimab introduction, the burden of bronchiolitis markedly decreased, and differences in early-life contact rates narrowed. These findings support the need for adaptive pediatric care planning and continuous surveillance of respiratory disease trends accounting for preventive strategies implemented at the community level.

The online version contains supplementary material available at 10.1186/s13052-026-02205-w.