CDC-Coauthored Study Shows Room for Improvement in Antiviral Use and Vaccination Rates for Flu in U.S. Hospitalized Children

May 4, 2022—A new CDC study published in Clinical Infectious Diseasesexternal icon underscores the burden of influenza (flu) among children (0-17 years old) during nine flu seasons after the 2009 H1N1 pandemic. Researchers looked at pediatric flu hospitalizations recorded in the US Flu Hospitalization Surveillance Network (FluSurv-NET) from 2010-2019. The study found that pediatric flu-related hospitalization rates were consistently highest among children younger than 6 months who are too young to get vaccinated, and that hospitalization rates decreased as children got older. However, hospitalized, older children had more severe outcomes (e.g., ICU admission, mechanical ventilation). This study reinforces the importance of vaccination among children 6 months and older as well as the importance of vaccination of pregnant people to protect infants (younger than 6 months old) from flu after birth until they are old enough to get vaccinated themselves.

The study also summarized several important changes that occurred over time, including increased use of molecular tests, increased use of flu antiviral treatment, and increased flu vaccination rates among children hospitalized with flu.

• The use of molecular tests to diagnose influenza in FluSurv-NET went from 49% to 81% over the study period, while use of other tests (e.g., rapid influenza antigen tests) declined.
• Antiviral use in hospitalized children increased from 56% to 82% among children younger than 5 years of age over the study period.
• Although flu vaccination coverage among hospitalized children improved over time, in these children hospitalized with flu it was lower (below 50%) than the annual national U.S. flu vaccination rates.

CDC recommends that all children get an annual flu vaccine and that all hospitalized children be treated promptly with influenza antivirals. Better compliance with CDC’s influenza vaccination and antiviral recommendations could help minimize the impact of flu on children.