Pneumococcal Vaccination in the United States: Current Recommendations and Strategies to Improve Vaccination Coverage

S treptococcus pneumoniae is the most commonly identified cause of lower respirato1y tract infections, a common cause of sepsis and meningitis, and a major cause of morbidity and mortality worldwide. In the United States, pneumococcal infections may cause more deaths each year than any other vaccine preventable disease (1) . Mortality for pneumococcal pneumonia with bacteremia is about 20% among adults and as high as 40% among the elderly. In spite of the impressive public health burden of pneumococcal disease, vaccines aga inst pneumococcus re main largely underutilized. The recent emergence of drug-resistant S pneumoniae places a new emphasis on the need for vaccination against pneumococcal infections. Clinically significant pneumococcal isolates with decreased susceptib ili ty to penicillin were first identified in the United States in the 1970s but were uncommon until the early l 990s (2). Data from active, populationbased surveillance in the United States during 1995 and 1996 show that in some areas over 20% and 10% of isolates were no longer susceptible to penicillin and cefotaxime, respectively (3). Concurrent with the emergence of strains res istant to beta-lactams, pneumococci with decreased susceptibility to other classes of antimicrobial agents also have become more prevalent. The emergence of resistant strains makes empirical treatment decisions more cha llenging for clin icians; as pneumococcal infections become more difficult to treat, assuring that patients at risk receive adequate vaccination is more important than ever.