[Pneumococcal vaccination--yes or no?]

Abstract

Invasive pneumococcal infections, defined as demonstration of Streptococcus pneumoniae in blood cultures or CSF, are frequent and associated with high mortality in risk groups. Risk groups are the over-65s, individuals with anatomic or functional asplenia, immunosuppressed patients, patients with haemotological neoplasias and HIV-infected subjects, as well as, in general, al sufferers from chronic cardiopulmonary disease, diabetics and patients with severe renal failure or nephrotic syndrome. The 23valent polysaccharide vaccine produces a reliable immune response in children aged over 2 years and adults. The immune response is diminished in severely immunocompromised subjects and in the elderly. Numerous clinical studies provide evidence of the effectiveness of pneumococcal vaccination in the he prevention of invasive pneumococcal infection. Pneumococcal vaccination is recommended for the above mentioned risk groups. It should be observed that for the group at most risk, i.e. heavily immunosuppressed and HIV-infected subjects, there are no convincing data on clinical effectiveness. Regarding non-bacteriaemic pneumococcal pneumonias there are only pointers to the possible usefulness of polysaccharide vaccines. Booster vaccination is not recommended by the manufacturers in view of the reportedly increased incidence of side effects. Studies show that side effects are not more frequent than with primary vaccination. A single revaccination is particularly indicated in status post splenectomy. The conjugate vaccines now under development will improve the efficacy of pneumococcal vaccination and will also be usable in children aged under 2 years.