Pneumococcal vaccination: current and future issues

Infection with Streptococcus pneumoniae remains a major global health burde n meaning the development of effective vaccines is urgently needed. The cur rent 23-valent polysaccharide vaccine has been shown to prevent pneumococca l pneumonia in immunocompetent young adults, but not in elderly persons. However, in prevention of invasive pneumococcal disease, the vaccine is eff icacious in the elderly and may also be effective in some groups of immunoc ompromised patients. The polysaccharide vaccine is, therefore, recommended in all older (greater than or equal to 55-65 yrs of age) adults and in youn g children (>2 yrs; of age) who have a high risk for pneumococcal disease. Revaccination can be safely performed and is recommended 5 yrs after the fi rst dose. In children <2 yrs of age, the new polysaccharide-protein conjugate vaccine s, including 7-11 serotypes, seem to be effective in the prevention of inva sive disease, severe pneumonia and serotype-specific (and vaccine-related t ypes) otitis media. The low serotype coverage, need for repeated doses, and high price, may decrease the usefulness of the new conjugates. However, th e included serotypes; correspond to those most often associated with penici llin resistance and vaccination is, therefore, a possible tool in limiting the spread of antibiotic-resistant pneumococci.