Prevention of Invasive Pneumococcal Disease: Problems Emerged After Some Years of the 13-Valent Pneumococcal Conjugate Vaccine Use.

Starting from 2010, the 13-valent pneumococcal conjugate vaccine (PCV13) was introduced in several countries. This paper discusses some of the problems recently emerged after PCV13 use and their clinical impact. The impact of PCV13 has been relevant and has saved millions of children and adults by severe infectious diseases. However, it seems likely that in the future, effectiveness of the vaccine might be even higher than that presently evidenced. This is because long-term administration of PCV13 to the pediatric population can favor a more extensive reduction of nasopharyngeal colonization with vaccine serotypes of both vaccinated and unvaccinated subjects and further reduce invasive pneumococcal disease in all the individuals (herd immunity). While waiting for new vaccines to be able to overcome the problem of a limited number of pneumococcal strains included in PCV13, it is recommended to increase pneumococcal vaccination coverage in the entire pediatric population.