Editor’s Note: Dr. Alex Eaton (he/him) is a resident physician in pediatrics at The Boston Combined Residency Program at Boston Children's Hospital and Boston Medical Center. He is interested in medical education and health disparities research, specifically pediatric pain management in the setting of historic practices of race-based medicine. Alex is planning to pursue a fellowship specializing in pediatric critical care. -Rachel Y. Moon, MD, Associate Editor, Digital Media, Pediatrics
Introduction
In the US, respiratory syncytial virus (RSV) is a major cause of hospitalization and death among young children. Historically, RSV and other respiratory infections have “surged” in the fall and waned by early spring, with a peak in December or January. However, the COVID-19 pandemic, and the public health measures enacted to curb disease spread, resulted in significant shifts in respiratory viral activity in our pediatric population. Many pediatric providers remember the chaos that was the winter of 2022, marked by constant, punishing waves of children sick with RSV. In a new article entitled, “Respiratory Syncytial Virus-Associated Hospitalizations in Children <5 Years: 2016–2022,” which is being early released this week in Pediatrics, Dr. Meredith McMorrow and colleagues from the Centers for Disease Control and Prevention and 7 other US institutions explain how these changes to RSV patterns may impact inpatient pediatric medicine for years to come (10.1542/peds.2023-065623).
Impact on the Youngest Children
Why is RSV important? RSV tends to cause severe lower respiratory tract disease in infants, with the highest hospitalization rates for children under 2 months of age. Comparatively, children who contract RSV after age 1 year tend to have milder illness.
Atypical RSV Seasons During the Pandemic
In March 2020, RSV infections plummeted as pandemic precautions took hold, leading to an unprecedented decline in hospitalizations from May 2020 to March 2021. An unusual RSV season followed in 2021, peaking in July and August, and extending through the end of the year. In 2022, RSV transmission rose early in summer, with a record peak nationwide October and November before declining rapidly. This intense, early, rise in hospitalizations overwhelmed many pediatric healthcare facilities.
Comparative Analysis: Pre-Pandemic vs. Pandemic Seasons
The article authors compared the demographic and clinical characteristics of children hospitalized with RSV during four pre-pandemic seasons (December 2016–September 2020) to those hospitalized in 2021 and 2022. Across the years, while infants under 2 months old bore the highest hospitalization burden, there was a significant increase in hospitalization rates in 2021 and 2022, driven primarily by hospitalizations of older children. And as is unfortunately nearly omnipresent in our healthcare system, the disease burden fell more heavily on children of color.
Despite increased hospitalization rates, severity of disease was comparable between pre- and post-pandemic seasons (measured by need for ICU admission, mechanical ventilation, and length of stay.) The relative lull in RSV exposure in 2020 for children aged 12-23 months may have contributed to this phenomenon.
Preventive Measures and Future Implications
The article has important implications for RSV prevention measures. Because disease is less severe in older children, these authors encourage the use of RSV prevention products, such as vaccination of pregnant people and use of long-acting monoclonal antibodies (i.e., the RSV “vaccine” for infants) to delay primary infection until after 12 months of age.
By understanding these shifts and maintaining robust preventive measures, we can better prepare for future RSV seasons and strive toward minimizing the impact of respiratory disease on pediatric health.
