Research conducted by the Carlos III Institute of Health (ISCIII) showed that the latest winter vaccination prevented 70% of influenza infections that would have been reported to primary care and 77% of influenza hospitalizations among children aged 6 months and older up to 1 year. 5 years.
An article presenting the results of the study was published in the Eurosurveillance journal of the European Center for Disease Prevention and Control (ECDC). Based on the study’s findings, which are consistent with those of other previous studies, the authors recommend continuing to increase influenza vaccination coverage in this age group.
The study was conducted on 1666 children under 5 years of age, of which 1364 were treated in medical institutions and 302 were hospitalized. Taken together, the results indicate good vaccine efficacy in both settings, although the small number of influenza-related hospitalizations in this pediatric population provides less confidence in the estimates regarding hospitalizations.
Medical centers highlight the good vaccine effectiveness achieved against the A(H1N1)pdm09 subtype, which circulated predominantly during the 2023-2024 season. and in particular against clade 5a.2a, despite the fact that clade 5a.2a. 1 was included in the vaccine recommended by the World Health Organization (WHO).
The study was conducted based on data from the Surveillance System for Acute Respiratory Infections (SiVIRA), which is coordinated by ISCIII in collaboration with the Ministry of Health and the Autonomous Communities and Cities.
The main authors of the work are Gloria Pérez Gimeno, Clara Mazagatos and Susana Monge, researchers from the National Center of Epidemiology (CNE) of the ISCIII, and Francisco Pozo from the National Center of Microbiology (CNM) of the institute. The event was also attended by researchers from the Network Center for Biomedical Research (CIBER), also dependent on ISCIII, and specialists from the health departments of autonomous communities and cities.
Globally, there are an estimated 109 million cases of influenza virus infection annually among children aged 0 to 5 years, an age group that is at risk of serious illness and which, in Spain, has the second highest number of hospitalizations for influenza, only lower. in people aged 65 years and older. In addition, children under 5 years of age play a key role in spreading the virus through the population and intensifying influenza epidemics.