ATLANTA — Providing the influenza vaccine to as many eligible schoolchildren as possible might reduce the burden of influenza in the entire community, Dr. Kathleen M. Neuzil said at a meeting on clinical vaccinology sponsored by the National Foundation for Infectious Diseases.
The current risk-based recommendations for vaccination are complicated, said Dr. Neuzil, with 12 influenza vaccination target groups currently identified by the Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices (ACIP). Adults may have a difficult time determining whether they are at high risk. Alternative strategies have been evaluated as a way to increase vaccination coverage.
Dr. Neuzil explained that while older adults are most likely to develop complications from influenza, children aged 5–14 years are the group most likely to have clinical disease.
In fact, absenteeism from school is the first marker of an influenza epidemic, and a 10% absenteeism rate is an effective marker for an epidemic (N. Engl. J. Med. 1987;298:587–92).
Given this epidemiology, several studies have investigated vaccinating all schoolchildren as a mechanism for protecting the whole community from influenza.
Starting in 1962, Japan vaccinated most children against influenza. The vaccination program was associated with a decrease in excess mortality, and when the program was discontinued in 1987, mortality increased (N. Engl. J. Med. 2001;344:889–96).
A schoolchild vaccination study involving 28 schools in the United States found a reduced influenza burden during the peak influenza week in the households of the 2,717 schoolchildren who received the live attenuated influenza vaccine during the 2004–2005 season, compared with children in control schools.
The results of the study, presented at the 2006 Pediatric Academic Society meeting, showed fewer episodes of influenza-like illnesses, fewer related physician visits, less frequent use of medications, and fewer school and work days missed in households of vaccinated children. Interestingly, 73% of children in the study were receiving influenza vaccine for the first time, indicating that the program was meeting an unmet need.
Between 30% and 56% of children in the target schools opted to receive the vaccination, with rates correlating with socioeconomic status.
This study “supports the theory that kids are integral in spreading flu,” commented Dr. Neuzil of the University of Washington in Seattle. She said that improving vaccination of existing target groups might be achieved through improved public awareness and provider education. The ACIP also is looking into establishing a universal vaccination recommendation, beginning with children.
At the meeting, which was also sponsored by Emory University, Dr. Katherine A. Poehling offered some additional suggestions for increasing influenza vaccinations in children. Providers should specifically recommend the vaccine to parents and educate them on when and why to vaccinate.
She told the story of a local practice that mentions the vaccine at three different points during a visit. They report that it's very hard to refuse after being told the same information three times, said Dr. Poehling of the Monroe Carell Jr. Children's Hospital at Vanderbilt University, Nashville, Tenn.
Dr. Poehling also suggested that clinicians educate parents about influenza vaccine throughout the year, because not all children will have a well-child visit between October and January.
Steps also should be taken to enhance access to the vaccine, such as reducing out-of-pocket costs and vaccinating children at all visits.
Walk-in clinics or flu shot clinics also can improve access, although the best strategies for each practice may vary.