News Author: Laurie Barclay, MD
CME Author: Charles P. Vega, MD
September 15, 2009 — The American Academy of Pediatrics (AAP) has updated current recommendations for routine use of trivalent seasonal influenza vaccine and antiviral medications for the prevention and treatment of influenza in children. The updated guidelines are published in the September issue of Pediatrics.
"Trivalent seasonal influenza immunization is recommended for all children aged 6 months through 18 years," write Joseph A. Bocchini Jr, MD, chairperson, and AAP colleagues. "Healthy children aged 2 through 18 years can receive either [trivalent inactivated influenza vaccine or live-attenuated influenza vaccine]."
The AAP recommends annual trivalent seasonal influenza immunization for all children aged 6 months through 18 years, including those who are healthy and those who have conditions that increase the risk for complications from influenza. Other groups for whom AAP recommends annual trivalent seasonal influenza immunization are healthcare professionals, pregnant women, and household contacts and out-of-home care providers of either children with conditions that place them at high risk or healthy children younger than 5 years.
Key Points for 2009 to 2010 Flu Season
Specific key points especially relevant for the 2009 to 2010 influenza season are as follows:
Annual trivalent seasonal influenza immunization is recommended for all children aged 6 months to 18 years of age. Clinicians should especially target children at high risk for influenza complications, such as those with chronic medical conditions or immunosuppression. The greatest influenza disease burden is in school-aged children, who are at significantly greater risk compared with healthy adults of needing influenza-related medical care. Lowering influenza transmission among school-aged children is anticipated to decrease influenza transmission to household contacts and community members.
To decrease the risk for exposure to influenza for young children, who are at serious risk for influenza infection, hospitalization, and complications, household members and out-of-home care providers of all children and adolescents at high risk and of all healthy children younger than 5 years of age should also receive annual vaccination against influenza. Use of influenza vaccine has not been approved for children younger than 6 months of age.
All children 6 months through 18 years of age, particularly those at high risk for complications from influenza, should be identified, and their parents should be notified that annual influenza vaccination is available and recommended.
The B vaccine strain has been changed in the trivalent seasonal vaccine for the 2009 to 2010 influenza season to match the anticipated predominant strain, based on global surveillance of circulating influenza strains.
The World Health Organization has declared a pandemic for the novel influenza A (H1N1) virus, which supports the need for ongoing development of a vaccine protective against this strain. Recommendations for the use of an additional monovalent pandemic influenza vaccine in the 2009 to 2010 season may in part be based on the novel strain’s pattern of spread in the Southern Hemisphere during the influenza season. Providers must be aware and updated regarding their local and state health department recommendations, which are available on the CDC Web site and the AAP Red Book Online Influenza Resource Page. The AAP Web site will also frequently post updated details on the H1N1 virus for pediatricians and families.
As soon as vaccine is available, even as early as August or September, all children should be offered seasonal influenza vaccine, because the protective response to vaccination should remain throughout the influenza season. Even after influenza activity has been confirmed in a community, however, immunization efforts should continue throughout the entire influenza season, which often extends even into March and beyond. Furthermore, there may be more than 1 peak of activity in the same season. Immunization through at least May 1 can therefore still protect vaccinees during that season, while offering sufficient opportunity to administer a second dose of vaccine to children needing 2 doses in that season.
The recommended number of trivalent seasonal influenza vaccine dose(s) is based on age, as follows:
Children 9 years and older who have not previously received trivalent seasonal influenza vaccine should only receive 1 dose in their first season of vaccination.
Children younger than 9 years of age who are given the trivalent seasonal influenza vaccine for the first time should receive a second dose during the same season and 4 weeks or more after the first dose.
Children younger than 9 years of age given only 1 dose of trivalent seasonal influenza vaccine in the first season they were vaccinated should receive 2 doses of trivalent seasonal influenza vaccine the following season and 1 dose each season thereafter. This recommendation applies only to the influenza season following the first year that a child younger than 9 years of age is given influenza vaccine, because data are not available for other scenarios of trivalent seasonal influenza vaccine.
Because concurrent circulation of multiple influenza strains with different susceptibility patterns is anticipated during the 2009 to 2010 influenza season, the recommended use of antiviral medications for chemoprophylaxis or treatment is more complex than in previous years. Treatment options include amantadine, rimantadine, oseltamivir, and zanamivir. Seasonal influenza A (H1N1) virus (A/Brisbane/59/2007) is resistant to oseltamivir and is susceptible to the other drugs. Pandemic influenza A (H1N1) virus, seasonal influenza A (H3N2) virus, and seasonal influenza B (B/Brisbane 60/2008, Victoria lineage) virus are resistant to amantadine and rimantadine and susceptible to oseltamivir and zanamivir.
To achieve the target immunization of all children 6 months through 18 years of age, healthcare professionals, influenza campaign organizers, and public health agencies should cooperate to develop and implement plans for expanding outreach and infrastructure. Some examples include creating walk-in influenza clinics, making vaccine available during all clinical hours, extending hours during vaccination periods, and collaborating with schools, child care centers, churches and other institutions to increase venues where vaccination can take place.
"Concerted effort among the aforementioned groups, plus vaccine manufacturers, distributors, and payers, also is necessary to appropriately prioritize administration of trivalent seasonal influenza vaccine whenever vaccine supplies are delayed or limited," the guidelines authors conclude. "Continued evaluation of the safety, immunogenicity, and effectiveness of [live-attenuated influenza vaccine] for young children is important. Development of a safe, immunogenic vaccine for infants younger than 6 months also would be valuable."
All authors have disclosed that they filed conflict of interest statements with the AAP, and any conflicts have been resolved through a process approved by the board of directors.
Pediatrics. Published online September 7, 2009.