Influenza and pneumococcal vaccination of the elderly: newer vaccines and prospects for clinical benefits at the margin.

The continued importance of pneumonia and influenza as a cause of hospitalization and death in the United States provides ample evidence of the need for more effective means of prevention. Recent reports have greatly enhanced our understanding of the impact of these infections as major contributions to the morbidity and mortality of respiratory disease. Other reports have provided new evidence of the clinical effectiveness of current influenza and pneumococcal vaccines and the cost effectiveness of vaccination. Together with studies on long-term outcomes of pneumonia patients, it is now clear that vaccination rather than pneumonia is truly "the old man's friend." These recent developments raise the question of what clinical benefits might be expected from new and improved influenza and pneumococcal vaccines. In all likelihood their marginal benefits will be small, and greater benefits might be achieved by overcoming problems in vaccine delivery and improving the implementation of public policies for vaccination.