Less than one-third of children with asthma between the ages of 2 and 17 years received the influenza vaccine during the 2004–2005 influenza season, according to the first national estimate of influenza vaccine coverage in children with asthma by the Centers for Disease Control and Prevention.
While this rate is approximately three times higher than that reported for nonasthmatic children, the “inadequate” numbers indicate “that opportunities for vaccination during health-care provider visits likely are being missed,” according to Susan M. Brim of the CDC's National Center for Environmental Health and her colleagues (MMWR 2007;56:193–6).
With data from the 2005 National Health Interview Survey (NHIS)—a cross-sectional, household interview survey in the United States—the CDC investigators analyzed influenza vaccine coverage rates for the 5,124 youth aged 2–17 years represented in the database and determined that 29% of children with current asthma had received the influenza vaccine for the September 2004-February 2005 influenza season, compared with 10.3% of their nonasthmatic peers.
Of the children with current asthma, vaccine coverage was highest—at 32.9%—in the 2− to 4-year-old age group, compared with 28% in both the 5− to 12-year-old and 13− to 17-year-old age categories. Children who had experienced an asthma attack or episode within the 12 months prior to the survey (35.9% of those with asthma) were more likely to have been vaccinated than children with current asthma but no past-year history of an asthmatic episode (20%). Children aged 5–12 years with current asthma and no past year history of an asthmatic episode had the lowest vaccination coverage rate, at 16.4%, in the asthma group, the authors reported.
When the data were analyzed based on the number of health care visits per child during the 12 months preceding the survey, influenza vaccine coverage among children with asthma was directly related to the number of visits. “Approximately 10.8% of children with current asthma who had one health-care visit in the preceding year were vaccinated, whereas 42.0% of children with [10 or more] visits were vaccinated,” Ms. Brim and her associates wrote.
Because the 2005 NHIS was the first to include questions on influenza vaccination in the child portion of the survey, “the results of this analysis cannot be compared with previous years,” according to the authors. “Analysis of NHIS data from 2006 and future years will allow determination of trends in national influenza vaccination coverage in children with asthma.”
Such monitoring is essential for the design of public health strategies for increasing influenza vaccination coverage that targets all children with asthma, particularly those with the lowest coverage rates, the authors stressed. Continued monitoring also will be necessary to determine whether and to what extent changes, such as the 2006 revision to Advisory Committee on Immunization Practices (ACIP) influenza vaccination recommendations to include all children between the ages of 6 and 59 months, will impact actual coverage rates, they noted.