Study Analyzes Cause of Australian RSV Epidemic in Infants in 2022

An Australian study, “Clinical, Genomic, and Immunological Characterization of RSV Surge in Sydney, Australia, 2022,” examined the causes behind an epidemic surge and did not find a relationship to a hypothesized “immune debt” as a result of public health measures taken during the COVID-19 pandemic. The 2022 epidemic in Sydney was driven by pre-existing viral lineages primarily of RSV-B, in contrast to recent USA outbreaks driven by RSV-A, according to the study published in the February 2024 Pediatrics (published online Jan. 16). Researchers analyzed 297 nasopharyngeal swabs discarded after routine diagnostic testing that were collected from RSV-positive infants (age <12 months) who presented with respiratory symptoms to Sydney Children’s Hospital Randwick, Australia between May and September 2022. The study revealed that in RSV-infected infants, over one-quarter of hospital visits by otherwise-healthy children resulted in admission and receipt of high-flow oxygen support. Researchers indicated their findings suggest that a more complex interplay of unknown factors, and not waning antibody-mediated immunity, led to the increased RSV case numbers and disease burden observed in 2022 outbreaks. RSV causes millions of hospitalizations and up to 118,000 child deaths per year globally, with annual epidemics typically occurring during winter months.  

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The American Academy of Pediatrics is an organization of 67,000 primary care pediatricians, pediatric medical subspecialists and pediatric surgical specialists dedicated to the health, safety and well-being of infants, children, adolescents and young adults.