Mar 8, 2007 (CIDRAP News) Only about 29% of the 6.5 million American children with asthma, a group at risk for influenza complications, received flu shots in the 2004-05 season, the Centers for Disease Control and Prevention (CDC) said today.
The figure comes from the first attempt to estimate flu vaccination coverage specifically in children with asthma, for whom the shots have been recommended since 1964, the CDC reports in the Mar 9 issue of Morbidity and Mortality Weekly Report.
Although children with asthma were nearly three times as likely to have been vaccinated as children without asthma, the finding indicates that "influenza vaccination coverage among children with asthma is inadequate and that opportunities for vaccination during health-care provider visits likely are being missed," the CDC says.
In 2005 the CDC added questions about flu vaccination in children to its National Health Interview Survey, an ongoing, in-person household survey of the US civilian population. In the interviews, information about one randomly selected child from each household is collected from an adult family member.
Responses from interviews conducted between March and August of 2005 were used to estimate vaccination coverage in the preceding flu season. A total of 5,124 children, aged 2 to 17 years, were included in the analysis; children were considered vaccinated if they had received a flu shot between September 2004 and February 2005. The article says 557 children, or about 10.9% of the sample, were reported to have asthma. Nationally, about 8.9% of children younger than 18about 6.5 millionhad asthma in 2005, the CDC says.
The survey revealed a vaccination rate of 29.0% (95% confidence interval [CI], 24.5% to 33.9%) for children with asthma and 10.3% (95% CI, 9.3% to 11.5%) for children without asthma. Among children with asthma, 2- to 4-year-olds had the highest rate, 32.9%, versus 28.0% for 5- to 12-year-olds and 28.8% for 13- to 17-year-olds.
Children who had asthma and had had an attack in the year preceding the interview had significantly higher vaccination coverage than those who had had no episodes in the preceding year: 35.9% versus 20.0% (P<.001). Vaccination coverage also increased with the number of medical visits in the preceding year.
Previously the CDC estimated a flu vaccination rate of 34.8% in 2004-05 for children with any of several risk factors for flu complications. That estimate, based on 685 children sampled in the CDC 's Behavioral Risk Factor Surveillance System, did not include a separate assessment of coverage in children with asthma.
The 2004-05 flu season brought an unexpected shortage of vaccine, when problems at a Chiron plant in England kept about 50 million doses off the US market. Because of the shortage, the CDC recommended prioritizing high-risk groups for vaccination, and children with asthma were included in the priority group of people with chronic medical conditions, the report notes.
The effect of the vaccine shortage on coverage in children with asthma is unknown, the CDC says. The prioritization advice might have contributed to the higher rate in asthmatic children than in children with no asthma, or the shortage might have caused lower vaccinate rates in all children, relative to other seasons.
The CDC says possible ways to boost vaccination rates include year-round scheduling of flu vaccination appointments and computerized reminder systems. In a 2006 study, vaccination coverage for children with asthma increased significantly from 23.2% to 35.1% after a year-round scheduling policy was adopted.
CDC. Influenza vaccination coverage among children with asthmaUnited States, 2004-05 influenza season. MMWR 2007 Mar 9;56(9):193-6 [Full text]