An overview of the clinical development of the 20-valent pneumococcal conjugate vaccine in adults

The 20-valent pneumococcal conjugate vaccine (PCV20) was developed to expand protection against vaccine-preventable disease caused by <i>Streptococcus pneumoniae</i> beyond the 13-valent pneumococcal conjugate vaccine (PCV13). This review summarizes the adult clinical development program of PCV20. Across studies, the safety profile of PCV20 was acceptable and similar to that of PCV13 and the 23-valent pneumococcal polysaccharide vaccine (PPSV23). Pivotal noninferiority comparisons of serotype-specific opsonophagocytic activity responses (PCV20 to PCV13 for the 13 matched serotypes; PCV20 to PPSV23 for the 7 additional serotypes) were conducted in pneumococcal vaccine‒naive ≥60-y-old adults to infer efficacy. Immunobridging of PCV20 responses to adults 60-64 y of age supports PCV20 use in adults 18 through 59 y of age, including those at increased risk of pneumococcal disease. Additionally, PCV20 elicited functional responses to all 20 vaccine serotypes in adults ≥65 y old who were previously vaccinated with PCV13 and/or PPSV23.