The recently published article by Shami et al. describes a cost-effectiveness analysis of sequential pneumococcal vaccination with 13-valent pneumococcal conjugate vaccine (PCV13) followed by 23-valent pneumococcal polysaccharide vaccine (PPSV23), compared with a single PPSV23 dose, in adults in Hong Kong. Sequential vaccination was cost-saving versus PPSV23 alone. The model assumed vaccine effectiveness (VE) of 0% for PPSV23 against all-cause non-bacteremic pneumonia; this was based on studies with flawed methodologies and studies that did not evaluate non-bacteremic pneumococcal disease. In recent studies and meta-analyses, PPSV23 VE pneumococcal pneumonia, including against non-bacteremic pneumococcal pneumonia, ranged from 27% to 64%. In other cost-effectiveness analyses, assumptions for PPSV23 VE against non-bacteremic pneumococcal pneumonia, had dramatic effects on cost-effectiveness estimates. Future analyses must carefully consider PPSV23 VE assumptions to ensure accuracy.
Keywords: PPSV23; Pneumococcal polysaccharide vaccine; cost-effectiveness.