Efficacy and effectiveness of pneumococcal polysaccharide vaccines and their use in industrialised countries.

Use of pneumococcal polysaccharide vaccines remains controversial, even though clinical trials have shown their efficacy in preventing invasive disease caused by vaccine serotypes in immunocompetent adults. Retrospective studies indicate these vaccines have about 50%-80% effectiveness for preventing invasive disease caused by vaccine serotypes, although effectiveness wanes over time and with age. The elderly, people living in institutions and those with chronic cardiac or respiratory disease, alcoholism or diabetes mellitus who are in relatively good health would benefit from vaccination; a polysaccharide vaccine program in the elderly has been shown to be cost-effective. In young children, polysaccharide vaccine should be evaluated as a booster to conjugate pneumococcal vaccines, which are likely to be available soon in industrialised countries. In view of the high rates of hospitalisation and of antimicrobial resistance in pneumococci, every effort should be made to increase coverage by pneumococcal polysaccharide vaccine in Australia, according to guidelines of the National Health and Medical Research Council.