Immunological Memory Against Pneumococcus Induced by 3 Infant PCV 13 Vaccination Schedules

The purpose of this study is to evaluate the establishment of immunological memory between the 3 different infant vaccination schedules with the 13-valent pneumococcal conjugate vaccine (PCV13) currently in use. We aim to determine the optimal schedule for the establishment of antigen-specific memory B-cell pool, which may serve as a correlate for longevity of immunological memory against vaccine serotypes. Moreover, we will study the transcriptome profiles expressed by peripheral lymphocytes during each immune response in an attempt to reveal immunological mechanisms beyond the antibody and circulating B cells level.