The 2019-2020 flu season was a bad flu season for children. Two antigenically drifted influenza viruses predominated and cases of influenza soared, resulting in the largest influenza epidemic in children in the United States since 1992. Pediatric Intensive Care Influenza Study investigators used a test-negative design to estimate the effectiveness of influenza vaccine in preventing critical and life-threatening influenza in children during that season. The good news: vaccination reduced the risk of critical influenza by 78% against H1N1pdm09 viruses that were well-matched to vaccine and by 47% against mismatched viruses. Vaccination was estimated to be 75% protective against antigenically drifted B-Victoria viruses. Overall vaccine effectiveness against critical illness from any influenza virus was 63% (95% confidence interval, 38%-78%).
While it might be tempting to attribute suboptimal immunization rates to vaccine hesitancy, ready availability remains an issue for some families. We need to eliminate barriers to access. While the AAP continues to emphasize immunization in the medical home, especially for the youngest infants, the 2022 policy statement suggests that vaccinating children in schools, pharmacies, and other nontraditional settings could improve immunization rates. To the extent feasible, we need to work with partners to support community-based initiatives and promote these to families who struggle to make it into the office.
Improving access is just one potential way to reduce health disparities related to influenza and influenza vaccination. Over 10 influenza seasons, higher rates of influenza-associated hospitalizations and intensive care unit admissions were observed in Black, Hispanic, and American Indian/Alaska Native people. These disparities were highest in children aged younger than 4 years and influenza-associated in-hospital deaths were three- to fourfold higher in Black, Hispanic, and Asian/Pacific Islander children, compared with White children. The reason for the disparities isn’t completely clear but increasing immunization rates may be part of the solution. During the 2020-2021 influenza season, flu immunization rates in Black children (51.6%) were lower than those seen in White (57.4%) and Hispanic children (58.9%).
The AAP’s Recommendations for Prevention and Control of Influenza in Children, 2022–2023, highlight a variety of evidence-based strategies to increase influenza immunization rates. These may provide a little inspiration for clinicians looking to try a new approach. If you wish to share your experience with increasing influenza immunization rates in your practice setting, please email me at Kristina.email@example.com.
Dr. Bryant is a pediatrician specializing in infectious diseases at the University of Louisville (Ky.) and Norton Children’s Hospital, also in Louisville. She is a member of the AAP’s Committee on Infectious Diseases and one of the lead authors of the AAP’s Recommendations for Prevention and Control of Influenza in Children, 2022–2023. The opinions expressed in this article are her own. Dr. Bryant discloses that she has served as an investigator on clinical trials funded by Pfizer, Enanta, and Gilead.