Figure 2. Participant disposition.  a Evaluable immunogenicity population for 13 matched serotypes.  b Evaluable immunogenicity population for 7 additional serotypes.  c Evaluable immunogenicity population for all 20 serotypes. See  Supplementary Appendix  for descriptions of evaluable populations. Abbreviations: AE, adverse event; PCV13, 13-valent pneumococcal conjugate vaccine; PCV20, 20-valent pneumococcal conjugate vaccine; PPSV23, 23-valent pneumococcal polysaccharide vaccine.