Burden of influenza in Spanish pediatric population and the benefit of vaccination

Abstract

Introduction

The burden of influenza in the paediatric population is often underestimated by healthcare professionals and the general population, mainly due to poor perception of its clinical importance at the individual level and its health impact at the healthcare level. The aim of this review was to collect data on the burden of paediatric influenza in Spain and to compare them with data of countries where vaccination strategies for healthy paediatric populations have been implemented.

Methods

We collected data on the burden of paediatric influenza in Spain through a systematic search of literature published between 2016–2021 (PRISMA methodology). We conducted a review of reports from the Spanish Influenza Surveillance System (SVGE) (2010–2011 to 2019–2020) and of international reports (from Canada, Finland, USA, and UK) through a systematic (2016–2021) and pragmatic search.

Results

1366 articles were obtained from the systematic searches by country; 26 met the inclusion criteria. According to the SVGE (Spain's Influenza Surveillance System), those < 15 years have the highest incidence of influenza per 100,000 population (cumulative-mean rate: 9457.9) compared to those ≥ 15 years (2285.6), and percentage of admission to the Paediatric Intensive Care Unit (PICU) greater than those > 65 years (mean: 29.1% vs. 17.5%). Hospitalisation of severe cases per 100,000 population in children aged 0–4 years and those > 65 years is similar (median: 20.2 vs. 28.4). Those aged < 15 years have a higher incidence rate per 100,000 population (213.3), in contrast to those aged 15–64 years (21.9) and those aged ≥ 65 years (65.2). In countries with paediatric vaccination programmes (USA, Finland, and UK) the burden of influenza in children is reduced by 40%–74%, whereas 50%-93.5-% of cases presenting to the ED, hospitalised, admitted to PICU, or dying from influenza are unvaccinated.

Conclusions

The burden of paediatric influenza in Spain includes a significant number of hospitalisations and PICU admissions and justifies the vaccination strategy recommended by the WHO since 2012. In countries with this recommendation, the vaccinated paediatric population is better protected against severe forms of influenza and potential benefits for reducing the burden of paediatric influenza in Spain can be extracted from their data.