Epidemiology of Invasive <EMPH TYPE="ITAL">Streptococcus pneumoniae</EMPH> Infections in the United States, 1995-1998<SUBTITLE>Opportunities for Prevention in the Conjugate Vaccine Era</SUBTITLE>

][3] The risk of disease is highest among young children, older adults, smokers, and persons with certain chronic illnesses. 4,5A 23-valent polysaccharide vaccine has demonstrated effectiveness against bacteremic infections in older children and adults. 6,7fforts to increase use of this vaccine in the United States have led to more vaccine use in some populations, 8 although coverage remains below the goal of 90% among persons aged 65 years or older. 9Polysaccharide vaccines do not protect children younger than 2 years, a limitation that has motivated efforts to evaluate new vaccines for this age group.Recently, a pneumococcal 7-valent conjugate vaccine was licensed for use in young children.In clinical trials, this vaccine was shown to prevent invasive pneumococcal disease when ad-