This study states that Acute respiratory infections (ARI) are the leading cause of morbidity and mortality of children under 5 years outside the neonatal period.1 The majority of ARIs are viral in origin, with influenza substantially contributing to outpatient and emergency department visits, hospitalizations, and even deaths in these children.1 Influenza is a vaccine-preventable disease and impacts all age-groups, with the highest risk of influenza-related complications in children under 2 years, adults older than 65 years, pregnant women, and individuals with underlying medical conditions.2 Worldwide, although influenza hospitalizations among the pediatric population are known to inflict a large burden, the exact number of global cases and hospitalizations attributed to influenza is not well described. In 2008, a systematic review estimated the global incidence of influenza in children under 5 years to be 90 million cases, with approximately one million severe cases.1 The uncertainties of global pediatric influenza-associated hospitalization burden estimates may be posited to the lack of standard worldwide reporting and testing.4 In response to the 2009 H1N1 pandemic and in an attempt to overcome the influenza surveillance gap, the World Health Organization (WHO) launched an initiative in 2011 to develop global standards for influenza surveillance, including a global case definition of severe influenza.5 The case definition was intended to capture hospitalizations related to influenza and is known as severe acute respiratory infection (SARI), defined as an acute respiratory illness. 

Reference link-