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Christopher Fleming

Analysis Of Clinical Trial Finds That Immunizing Children At School Reduces Influenza Incidence And Saves Money

Conclusions Support Expansion Of Influenza Immunization Recommendations To School-Age Children

Bethesda, MD -- School-based immunization of students ages 5-18 can be a cost-effective way of fighting influenza. That’s the conclusion of a study published today on the Health Affairs Web site. http://content.healthaffairs.org/cgi/content/abstract/hlthaff.27.2.w96

In one large multistate trial, school-based immunization saved an estimated $171.96 per student-household over the course of a flu season, say a team of researchers led by Jordana Schmier of Exponent, a research organization based in Menlo Park, CA. Indeed, the researchers found that reductions in direct and indirect flu-related costs during the peak week of flu season alone offset the incremental costs of school-based immunization.

“Current influenza prevention policies don’t target school-age children for vaccination because they aren’t considered a high-risk population -- they’re not at the same risk for flu-related illness and death as groups such as older adults and very young children. However, what this reasoning ignores is the key role that school-age children play in spreading influenza to other members of their household and others in the community,” said Schmier.

In February, the Advisory Committee on Immunization Practices of the Centers for Disease Control and Prevention is considering recommendations to add school-age children to the groups that should be immunized against influenza. “Our study shows that immunizing students could prevent influenza and save money,” Schmier said.

Previous research has shown that immunizing students leads to lower levels of health care use and less absenteeism from work and school among members of immunized students’ households. Some studies have nevertheless suggested that immunizing students is not cost-effective, but “these studies assumed office-based administration of flu vaccine and therefore did not incorporate the efficiencies of mass immunization” through school-based vaccination programs, Schmier and her colleagues write. The studies also did not have complete data on the spread of flu within households and all of the resulting direct and indirect costs, the researchers say.

In Trial Of School-Based Flu Immunization, Savings In
Flu-Related Costs More Than Made Up For Vaccination Costs

Schmier and her colleagues conducted a cost-benefit analysis of a four-state trial in which schools were randomly assigned to an “intervention group” providing students with intranasal live attenuated flu vaccines and a control group not doing so. The trial, which has been previously described in the New England Journal of Medicine, was conducted during the 2004-2005 influenza season under the direction of James King, a professor of pediatrics at the University of Maryland School of Medicine.

King is a coauthor on the Health Affairs paper. Other coauthors include Kristin Nichol, a core investigator at the Center for Chronic Disease Outcomes Research, Minneapolis Veterans Affairs Medical Center; and Parthiv Mahadevia, senior director, Health Outcomes and Pharmacoeconomics, at MedImmune Inc. MedImmune produces the vaccine, FluMist, used in the trial.

In phone surveys during the peak week of the flu season, 17 percent of households with students in the intervention schools reported having a child with a flu-like illness, compared with 26 percent of households in control schools. Eight percent of households in the intervention group reported an adult with flu-like illness, as opposed to 13 percent of control households.

Peak-week vaccination costs in intervention schools (where almost half of all students were vaccinated) were $41.66, versus $5.58 in control schools (where 2 percent of students reported being vaccinated outside of school). However, this difference was more than made up for by the savings intervention-school households achieved in direct and indirect flu-related costs. During the peak week, intervention households used only $57.63 in health care resources to treat influenza, compared with $75.50 for control households. Intervention households incurred only $64.48 in flu-related indirect costs such as caregiving and absences from school and work, compared with $81.97 for control households.

The difference in costs during the peak week of flu season between intervention and control households was small: only 71 cents. However, over the course of the entire flu season the difference would likely be magnified: Intervention households would be expected to incur costs of $759.92, versus $931.88 for control households -- a $171.96 difference. “The major cost disadvantage for intervention schools is the costs of the vaccine themselves. But by peak week, most students who are going to be immunized have already received their vaccines, leaving intervention schools to reap the savings from their higher vaccination rate for the rest of the flu season,” Schmier explained.

You can read the article by Schmier and coauthors at




Health Affairs, published by Project HOPE, is the leading journal of health policy. The peer-reviewed journal appears bimonthly in print with additional online-only papers published weekly as Health Affairs Web Exclusives at www.healthaffairs.org.


©2008 Project HOPE–The People-to-People Health Foundation, Inc.