Pneumococcal vaccination strategies in adult population: perspectives with the pneumococcal 13 - valent polysaccharide conjugate vaccine.

Streptococcus pneumoniae (Sp) is a leading cause of infection in people of all ages worldwide, determining a significant impact because of its relatively high incidence rate, the associated economic costs, and the high case-fatality rates. More attention has to be paid for elderly and people with one or more risk factors, in order to reduce health costs and pneumococcal hospital admissions. Moreover, the increasing incidence of antibiotic-resistant Sp strains is a source of concern for its relevant clinical importance in health-care settings. At present, the 23-valent polysaccharide (PPV23) vaccine has shown some limits in terms of protection in the elderly population and against invasive diseases, among adults affected with chronic diseases, non-bacteriemic pneumonias and with immune suppression, in particular in adults with HIV. In December 2011, FDA licensed the 13-valent pneumococcal conjugate vaccine (PCV13) for prevention of pneumonia and invasive diseases (IPDs) in adults aged ≥50 years. The same decision was concomitantly assumed in Europe by EMA. PCV13 has shown superior results both in terms of immunogenicity and of adequate stimulation of a stable and long-lasting immunological memory. European recommendations for PCV13 vaccination in adults are still heterogeneous between Countries. The availability of PCV13 for adults offer a new and promising tool against Sp IPDs and non-IPDs, especially in elderly and at risk populations.