Pneumococcal Vaccination in Adults: What Can We Learn From Observational Studies That Evaluated PCV13 and PPV23 Effectiveness in the Same Population?

Introduction: Fifteen and 20-valent pneumococcal conjugate vaccines (PCV15; PCV20) were recently licensed to prevent pneumococcal disease in adults. In the absence of efficacy or effectiveness data for these new vaccines, studies comparing 23-valent pneumococcal polysaccharide vaccine (PPV23) and PCV13 might help inform decision-making on how to best implement expanded-valency PCVs. Compar-ing PPV23 and PCV13 is problematic, as no head-to-head clinical trials evaluated efficacy. Comparing effectiveness results across observational studies that vary by population, design, and outcomes is diffi-cult. To address these limitations, we undertook a narrative review of studies that assessed PPV23 and PCV13 vaccine effectiveness (VE) in the same adult populations.Methods: We conducted a literature search in PubMed and Google Scholar and screened 525 studies using a standardized evaluation framework.Results: Nine studies met inclusion criteria, all from high-income countries. None evaluated invasive pneumococcal disease (IPD) alone. VE against vaccine-type pneumococcal pneumonia ranged from 2 to 6% for PPV23 and 41 to 71% for PCV13. VE against pneumococcal pneumonia or severe pneumococcal disease (IPD or pneumococcal pneumonia) ranged from -10 to 11% for PPV23, 40 to 79% for PCV13, and 39 to 83% for sequential PCV13/PPV23. VE against all-cause pneumonia or lower respiratory tract infection ranged from -8 to 3% for PPV23 and 9 to 12% for PCV13.Conclusions: Overall, PCV13 demonstrated better protection than PPV23 against pneumococcal disease and all-cause respiratory outcomes in the included studies. Where evaluated, sequential PCV13/PPV23 vaccination showed little benefit over PCV13 alone. Results support the use of PCVs to protect against pneumococcal disease and respiratory infections in adults.(c) 2023 The Author(s). Published by Elsevier Espana, S.L.U. on behalf of SEPAR. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Automated summary

This narrative review compared the effectiveness of 23-valent pneumococcal polysaccharide vaccine (PPV23) and 13-valent pneumococcal conjugate vaccine (PCV13) in adults. The study found that PCV13 was more effective than PPV23 in preventing pneumococcal disease and respiratory infections. The sequential PCV13/PPV23 vaccination showed little benefit over PCV13 alone. The results support the use of pneumococcal vaccines to protect against pneumococcal disease and respiratory infections in adults.