New data from the Centers for Disease Control and Prevention show that, while older children are getting seasonal influenza vaccinations in greater numbers compared with the previous flu season – mostly because of H1N1 concerns – vaccination coverage rates for the youngest, most vulnerable age group – infants – have remained the same.
According to the CDC's Morbidity and Mortality Weekly Report, seasonal flu vaccination rates among children across all age groups (6 months to 18 years) improved overall in 2009–2010. The average vaccination coverage with one or more seasonal influenza doses increased to 26.3%, compared with 20.8% of all children for the 2008–2009 season. The researchers also determined that full vaccination coverage was low during the 2009–2010 season, ranging from 34.7% among children aged 6–23 months to 15.3% among children aged 13–18 years (MMWR 2010;59:1266–9).
These data are also helping the agency find out if efforts by the CDC Advisory Committee on Immunization Practices (ACIP) to expand its seasonal influenza vaccination recommendations to include all children aged 5–18 years "no later than the 2009–10 season" were fruitful.
The researchers used state data from the National H1N1 Flu Survey and the Behavioral Risk Factor Surveillance System (BRFSS) and from eight sentinel geographic regions (subsets of Arizona, Colorado, Michigan, Minnesota, Oregon, and Wisconsin; the entire state of North Dakota; and all of New York City). Vaccination with the influenza A(H1N1) 2009 monovalent vaccine was not included in this report, the researchers wrote.
Children aged 5–12 years showed the largest increase in vaccination coverage − 19.0% to 27.1% over the last two flu seasons – while coverage among children 6–23 months only increased from 55.2% in the 2008–2009 season to 55.7% in 2009–2010. Seasonal flu vaccination coverage among children aged 2–4 years and 13–18 years increased at similar rates: 38.4% (from 33.0% in 2008–2009) and 15.3% (from 10.9%), respectively.
"The increase in coverage from the 2008–09 season to the 2009–10 season among older children and adolescents could reflect the usually observed increase in vaccination coverage with newly recommended vaccines, increased awareness of influenza vaccination because of the 2009 H1N1 pandemic, or other reasons," the report said.
"These findings highlight the need to identify varied strategies and venues for delivering influenza vaccine to different age groups of children to increase vaccination coverage," the researchers added.
The CDC recommended new strategies and continued implementation of proven existing strategies that may include "vaccinating later in the season (January-March), standing orders, reminder/recall notifications, parental education about vaccination, and use of school-located vaccination programs."
In other influenza news announced in the same weekly report (MMWR 2010;59:1270–3), the CDC said that, for this time of year, low levels of influenza activity are currently being reported in the United States (July 13-Sept. 25, 2010), with the majority of it seasonal influenza. Meanwhile, there has been typical seasonal influenza activity in the southern hemisphere, as well as influenza activity in tropical areas, "with a mix of 2009 influenza A (H1N1), influenza A (H3N2), and influenza B viruses cocirculating."