Epidemiologic Benefits of Pneumococcal Vaccine Introduction into Preventive Vaccination Programs

Vaccination against pneumococci is one of the most effective methods of preventing pneumococcal diseases. Currently, 10- and 13-valent conjugate vaccines (PCV10 and PCV13) and 23-valent polysaccharide vaccine (PPSV23) are used. Only the conjugate vaccines are used in children. The PCV can be used both in children and adults, but children can receive only PCV. A side effect of vaccination was that bacterial serotypes not included in a vaccine started increasingly emerging in pneumococcal infections, replacing the serotypes eliminated by the vaccine. The basic vaccination schedule consists of three or four doses, according to the country's recommendation. In Poland, it consists of two primary doses followed by a supplementary dose of the PCV-10, with some modifications in case of specific risk factors. The use of preventive vaccinations has helped reduce antibiotic resistance, as serotypes characterized by a rapid acquisition of drug resistance are included in the vaccine serologic spectrum, making their environment prevalence decrease. The research is currently underway on conjugate vaccines that contain a greater number of bacterial serotypes and on more universal vaccines that would eliminate the emergence of new serotypes.