Trends in U.S. hospitalizations and inpatient deaths from pneumonia and influenza, 1996-2011

In this nationally representative study, PI hospitalizations and inpatient deaths decreased in U.S. between 1996 and 2011. There is a temporal association with the introduction and widespread use of pneumococcal conjugate vaccines, and the expansion of the target group for annual influenza vaccination to include all persons ≥6 months of age, while it is difficult to attribute these changes directly to specific vaccines used in this era.