RSV burden and prevention in children in LMICs

The RSV GOLD-ICU Network study, published by the RSV GOLD-ICU Network collaborators in this issue of The Lancet Global Health, 1 showed consistent respiratory syncytial virus (RSV) positivity (614 [29•0%; range 23•0-38•2] of 2118 children) among children younger than 2 years admitted to paediatric intensive care units with extended severe acute respiratory illness (eSARI) across ten low-income and lower-middle-income countries (LMICs) that were eligible for support from Gavi, the Vaccine Alliance.Among 30 (5%) of 608 children who died from RSV infection, only 16 (53%) were provided mechanical ventilation, probably because such resources were not available at the referral hospital.These data add to findings from the Pneumonia Etiology Research for Child Health study that RSV was the most common cause of severe and very severe pneumonia in children younger than 5 years across seven LMICs 2 and from the Child Health and Mortality Prevention Surveillance study that RSV was an important cause of death among young infants in LMICs.3 However, restricting enrolment to the local respiratory virus season, absence of testing for respiratory virus co-infections, and having 364 (60%) of 608 children from a single country-Nepal-might reduce the generalisability of their findings.Despite these limitations, the RSV GOLD-ICU Network study adds to increasing literature indicating that RSV is among the most common causes of severe respiratory disease in infants across all countries and income strata, 4 and is consistent with findings from the Global Burden of Disease Study that one in every 50 deaths in children aged 0-60 months is attributable to RSV. 5 The expanded eSARI surveillance approach described in this study complements broader RSV-surveillance initiatives, including integration of RSV sentinel surveillance into existing respiratory-virus sentinel surveillance.6 Routine RSV surveillance will provide crucial data to show RSV seasonality and disease burden and measure the effects of introducing RSV prevention products.In 2022 and 2023, a maternal RSV vaccine (bivalent RSV prefusion F vaccine) and a long-acting monoclonal antibody (nirsevimab) were approved by the European Medicines Agency, the US Food and Drug Administration, and other regulatory authorities on the basis of data indicating safety and efficacy in preventing severe RSV in young infants.7,8 Although country-specific use of products and schedules vary, early introduction of nirsevimab has shown high product effectiveness 9 and public health