In February 2000, a 7-valent pneumococcal polysaccharide-protein conjugate vaccine (Prevnar, marketed by Wyeth Lederle Vaccines) was licensed for use among infants and young children. CDC's Advisory Committee on Immunization Practices (ACIP) recommends that the vaccine be used for all children aged 2-23 months and for children aged 24-59 months who are at increased risk for pneumococcal disease (e.g., children with sickle cell disease, human immunodeficiency virus infection, and other immunocompromising or chronic medical conditions). ACIP also recommends that the vaccine be considered for all other children aged 24-59 months, with priority given to a) children aged 24-35 months, b) children who are of Alaska Native, American Indian, and African-American descent, and c) children who attend group day care centers. This report includes ACIP's recommended vaccination schedule for infants at ages 2, 4, 6, and 12-15 months. This report also includes a pneumococcal vaccination schedule for infants and young children who are beginning their vaccination series at an older age and for those who missed doses. In addition, this report updates earlier recommendations for use of 23-valent pneumococcal polysaccharide vaccine among children aged > or =2 years. Among children aged 24-59 months for whom polysaccharide vaccine is already recommended, ACIP recommends vaccination with the new conjugate vaccine followed, > or =2 months later, by 23-valent polysaccharide vaccine. Conjugate vaccine has not been studied sufficiently among older children or adults to make recommendations for its use among persons aged > or =5 years. Persons aged > or =5 years who are at increased risk for serious pneumococcal disease should continue to receive 23-valent polysaccharide vaccine in accordance with previous ACIP recommendations.