Wang X, Li Y, Deloria-Knoll M, et al. - In this systematic review and modelling study, researchers estimated the age-stratified human metapneumovirus-associated acute lower respiratory infection (ALRI) global incidence, hospital admissions, and mortality burden in children younger than 5 years. They estimated the global burden of human metapneumovirus-associated ALRIs in children younger than 5 years from a systematic review of 119 studies published between January 1, 2001, and December 31, 2019, and a further 40 high-quality unpublished studies. Infants younger than 1 year of age have disproportionately high risks of severe human metapneumovirus infections, similar to respiratory syncytial virus and influenza virus, in all World Bank income regions and all child mortality settings. Infants younger than 6 months of age are at higher risk of death from human metapneumovirus-associated ALRI in low-income and lower-middle-income countries than older children and those in upper-middle-income and high-income countries. The mortality estimates indicate the value of infant intervention strategies in all settings, and warrant continued efforts in low-income and lower-middle-income countries to improve the outcome of human metapneumovirus-associated ALRI among young infants.