Objective: To estimate the additional primary care visits needed for universal influenza vaccination of all US children and adolescents if all vaccinations occurred in primary care settings.
Design: Cross-sectional design.
Setting: Well-child care and other visits to primary care practices from the 2003-2004 Medical Expenditure Panel Survey.
Participants: Children aged 5 to 18 years (n = 3047) with a usual source of care. Main Outcome Measure Percentage of children needing 0, 1, or 2 additional visits to be immunized against influenza in a 3-, 4-, or 5-month vaccination window.
Results: In a 3-month window, if only well-child care visits were used for first immunization, 97% of 5- and 6-year-olds and 98% of 7- and 8-year-olds would need 1 or 2 additional visits for complete vaccination; 95% of 9- to 18-year-olds would need 1 visit. If instead all visits were used for immunization, 90% of 5- and 6-year-olds and 91% of 7- and 8-year-olds would need 1 or 2 visits; 78% of 9- to 18-year-olds would need 1 visit. Expanding the window to 4 or 5 months slightly reduces the need for additional visits. Nationally, using all opportunities for vaccination, 42 million additional visits would be needed in a generous 5-month window.
Conclusions: Most children and adolescents would need additional visits for universal influenza vaccination, even if all existing visits were used as vaccination opportunities. Efficient methods for vaccinating large numbers of children and adolescents are needed if primary care practices are to provide influenza vaccine for all children.