GAITHERSBURG, Md., Dec. 13 /PRNewswire-FirstCall/ -- Research published in The New England Journal of Medicine shows that school-based influenza vaccination programs may represent an effective and feasible strategy to help lessen the impact of seasonal influenza on households and communities. The study involving more than 15,000 schoolchildren found that households with children who attended schools with vaccination programs (intervention schools) reported significantly fewer flu-like symptoms than households with children who attended schools without such programs (control schools). All vaccinated children in the study received FluMist(R) (Influenza Virus Vaccine Live, Intranasal), which is delivered as a nasal mist. The study of 28 schools in four states was led by researchers from the University of Maryland School of Medicine and supported by a grant from MedImmune, Inc. .
"We know that healthy children are an important vector of flu in our society," said lead study investigator James C. King, M.D., professor of pediatrics at the University of Maryland School of Medicine. "Our research confirms that school-based vaccination programs can effectively reduce the spread and impact of influenza not only in vaccinated children, but in households and communities, as well."
School-Based Vaccination Programs Reduce Household Incidence and Impact of Influenza
Dr. King and his colleagues found that households with students attending intervention schools -- regardless of whether the children themselves had been vaccinated -- were significantly less likely to report fever or influenza-like illness during the community's peak influenza week than household members of children who attended control schools. In intervention school households, children were 23 percent less likely to report any fever or flu-like illness (relative reductions based on observed rates of 40 percent vs. 52 percent for children in intervention and control groups, respectively). Adults in intervention school households were 27 percent less likely to report these symptoms (relative reduction based on observed rates of 32 percent vs. 44 percent). In addition, intervention school households were 38 percent less likely to report the use of prescription drugs and 31 percent less likely to report the use of over-the-counter medication during the peak flu week. All of these findings were statistically significant: p < 0.001.
In addition, researchers found that households with children who attended schools with vaccination programs reported missing approximately 2 fewer school days per 100 school days during the flu season (4.34 vs. 6.63 days) than households with students in schools without programs. While not statistically significant, there was a trend toward adults missing fewer workdays due to being ill or staying home to care for a sick child.
"From a public-health perspective, this study reveals that there is a significant clinical benefit from school-based immunization of healthy children using FluMist," said Frank Malinoski, M.D., PhD, MedImmune's senior vice president of medical affairs. "Data suggest that school-based vaccination programs may represent a viable approach to reducing the burden of seasonal influenza in the community at large, and the needle-free administration of FluMist may help make mass vaccinations more feasible."
Influenza disease is a leading cause of vaccine-preventable death in children throughout the U.S.(1,2) Because children spend a large part of their day in close contact with other children in school or day care, they are more likely to get the flu than people in other age groups. In fact, children aged 5-14 years are nearly four times more likely to get the flu than adults.(3) As a result, children play a significant role in transmitting influenza to their family and community, many of whom are at high risk for influenza complications.(4) This study adds to the growing body of evidence that increasing influenza vaccination rates, particularly among healthy children, may help to reduce the incidence of disease and complications in vaccinated individuals as well as the larger community.
Researchers noted a modest but statistically significant increase in influenza-like symptoms and non-prescription drug use after vaccination. However, the lack of concurrent increases in the use of prescription medications or physician-office visits suggested that these symptoms were often mild. There was no increase in episodes of wheezing.
Researchers also observed that members of intervention-school households (both children and adults) had higher rates of hospitalization per 100 persons than did those in control-school households. However, post hoc analyses (comparing households with children who were vaccinated with those households with children who were not vaccinated) did not reveal a statistically significant difference in hospitalizations for either children or adults. This suggests that the reason for hospitalization was unrelated to the vaccine.
Study Included Data on More Than 15,000 Students across Four States
To conduct the study, researchers first identified 24 public elementary schools and 4 parochial schools (kindergarten through eighth grade) in Maryland, Texas, Minnesota and Washington State. Schools were then grouped into clusters of two or three, matched for geographic characteristics and students' ethnic and socioeconomic backgrounds. In each of the 11 clusters, one school was selected as the intervention school, and the remaining schools were designated as controls. In intervention schools, FluMist was offered at no charge to all healthy children 5 years of age or older in the fall of 2004.
Researchers then waited until the estimated peak flu week in each community (as determined prospectively using statistical models), and distributed questionnaires to all households with children in intervention or control schools immediately following this projected "peak flu week." The survey asked questions related to the influenza-vaccination status of household members and cases of influenza-like illness experienced during the previous week (projected "peak flu week").
In total, 47 percent (2,717 of 5,840) of students in intervention schools received FluMist. The study compared data on these students to 9,451 students who attended control schools. Questionnaires were returned by 77 percent of households with children in intervention schools and 83 percent of households with children in control schools.
About FluMist
FluMist is indicated for active immunization for the prevention of disease caused by influenza A and B viruses in healthy children and adolescents, 5 to 17 years of age, and healthy adults, 18 to 49 years of age. There are risks associated with all vaccines, including FluMist. Like any vaccine, FluMist does not protect 100 percent of individuals vaccinated. In studies of people between the ages of 5 and 49 years, runny nose was the most commonly reported side effect. Other common side effects included various cold-like symptoms, such as headache, cough, sore throat, tiredness/weakness, irritability, and muscle aches.
FluMist should not be used, under any circumstances, in anyone with an allergy to any part of the vaccine, including eggs; in children and adolescents receiving aspirin therapy; in people who have a history of Guillain-Barre syndrome; and in people with known or suspected immune system problems. Pregnant women and people with certain medical conditions, asthma, or reactive airways disease should not get FluMist.
Please see the Prescribing Information at http://www.flumist.com/pdf/prescribinginfo.pdf, visit http://www.flumist.com/, or call 1-877-633-4411 for additional information.
About MedImmune, Inc.
MedImmune strives to provide better medicines to patients, new medical options for physicians, rewarding careers to employees, and increased value to shareholders. Dedicated to advancing science and medicine to help people live better lives, the company is focused on the areas of infectious diseases, cancer and inflammatory diseases. With more than 2,500 employees worldwide, MedImmune is headquartered in Maryland. For more information, visit the company's website at http://www.medimmune.com/.
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influenza: recommendations of the Advisory Committee on Immunization
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