Childhood Hib vaccination and pneumonia and influenza burden in US seniors.

This analysis examines the potential for the elderly to receive indirect protection from pneumonia and influenza (P&I) from vaccination of children. Using data from the Centers for Medicare and Medicaid Services, the National Immunization Survey, and the Behavioral Risk Factor Surveillance System, mixed-effects models were used to assess associations between vaccination coverage and P&I on the state level overall and by urbanicity and income. As vaccination coverage in children increased, the state-level P&I rates in seniors decreased (beta=-0.040, -0.074 to 0.006), where beta represents the expected change in the logged age-associated rate of disease increase for a one-percentage point increase in vaccination coverage. Increasing vaccination coverage in the elderly was associated with an increase in P&I rates (beta=0.045, 0.011-0.077) in seniors. The degree of association was more prominent in urban and high income areas. The consistent associations between influenza in the elderly and vaccination coverage in children suggest that routine vaccination of children may impart some indirect protection to the elderly. 2010 Elsevier Ltd. All rights reserved.