Flu Immunizations Up, Hospitalizations Down in Children

Flu vaccinations increased while hospitalizations for flu decreased among children, although ER visits increased

/ Author:  / Reviewed by: Robert Carlson, M.D Beth Bolt, RPh

(RxWiki News) Kids aren't the biggest fans of vaccinations — particularly the needles that come with them. But those needles may be keeping many kids free from the flu and out of the hospital.

Beginning in 2004, yearly flu immunizations were recommended for all children over the age of 6 months. The flu vaccination rate increased significantly among children in recent years, while flu-related hospitalizations decreased and emergency room visits increased.

“Influenza still causes substantial burden in young children," the authors of this study wrote. "Optimal vaccine uptake with good match between circulating and vaccine strains has the potential for reducing disease burden in young children.”

A research team led by Marie R. Griffin, MD, MPH, of the Department of Health Policy at Vanderbilt University Medical Center in Nashville, TN, studied immunization trends and hospital visits in children aged 6 to 59 months in Davidson County, TN.

The research period covered flu seasons from 2000 to 2001 through 2010 to 2011. In 2000, Dr. Griffin and colleagues found that only 6 percent of the children had been immunized against the flu. By 2010, the immunization rate was 38 percent.

During the study period, hospitalizations for flu-related visits ranged from a low of seven in the 2002 to 2003 season to a high of 60 in the 2003 to 2004 season. Flu season generally runs from late fall to spring.

Flu vaccines are manufactured well ahead of flu season, based on predictions of the most likely flu strains. In some years, the flu virus changes or a strain can be much stronger than predicted. The flu vaccine can be less effective in those years.

These researchers noted that all the years in which hospitalization rates were higher than average had either low immunization rates or a poor match between the vaccine and the flu strain.

Flu-related ER visits among children (in which the children did not have to be admitted to the hospital) in the study group ranged from 351 in 2002 to 2003 to 2,324 in 2003 to 2004. ER visits for flu-related problems actually increased as immunization rates increased.

Dr. Griffin and team noted that increased use of the ER could have been due to changes in insurance coverage. Other possible factors were a decrease in the availability of outpatient care from clinics or doctors’ offices, sending people to the ER for treatment.

An increased awareness of the flu — as opposed to the common cold or other viral illnesses — might also have increased ER visits, Dr. Griffin and team noted.

This study was published online Dec. 8 in Pediatrics.

The Centers for Disease Control and Prevention and the National Institutes of Health funded the research.

Study author Dr. H. Keipp Talbot received research funding from Sanofi-Pasteur and MedImmune/AstraZeneca. Dr. William Schaffner was a consultant for Sanofi-Pasteur. Dr. Kathryn M. Edwards was a member of a Data Safety Monitoring Board for Novartis. Dr. Katherine A. Poehling received research funding from BD Diagnostics and MedImmune, and support from the National Institutes of Allergy and Infectious Diseases and Wachovia Research Foundation. Dr. Griffin received support from MedImmune. Several of these companies manufacture flu vaccines or medications used to treat the flu.

Review Date: 
December 6, 2014
Last Updated:
December 9, 2014