Introduction

Prevenar 13® (PCV13) has been evaluated in 6 pivotal clinical trials in 6198 patients ≥50 years of age (of which 5667 patients received at least 1 dose of Prevenar 13® [PCV13]).^1,2 The immune responses were evaluated using the OPA as the primary evaluation parameter, which is a better correlate of the functional efficacy of antibodies. This is important for older adults, because the antibodies generated by vaccination may not always be functional, due to the changes in immunosenescence.^3,4

Sanford et al reviewed the immunogenicity studies of PCV13 in adults; a total of 6 studies were reviewed. All 6 studies were randomised multicentre trials. Participants in these studies were either healthy adults or immunocompetent adults with chronic medical conditions and were either PPSV23 vaccine–naïve or vaccinated with PPSV23 at least 5 years earlier to the study. In the case of pneumococcal vaccine–naïve adults 60 to 64 years of age and adults ≥70 years of age who were previously vaccinated, the immune response provoked by PCV13 was non-inferior to that of PPSV23. For the majority of serotypes common to both PCV13 and PPSV23, PCV13 provoked a stronger immune response as compared with PPSV23. As compared with PPSV23 which does not include serotype 6A, more PCV13 recipients had a ≥4-fold increase in serotype 6A OPA GMTs. Recipients of PCV13 met superiority criteria for most serotypes. For adults 50 to 59 years of age, the immune response to PCV13 was non-inferior to that observed in adults 60 to 64 years of age. Administration of PCV13 and PPSV23 in different sequences indicated that PCV13 should be administered first, followed by PPSV23. The adverse events, such as muscle pain, swelling, headache, rash and chills, within 14 days of vaccination, were of mild-to-moderate severity. Serious adverse events were observed in 0.4% to 1.7% of PPSV23 recipients and 0.2% to 1.4% of PCV13 recipients.²

GMT, geometric mean titre; OPA, opsonophagocytosis assay; PCV, pneumococcal conjugate vaccine; PPSV23, 23-valent pneumococcal polysaccharide vaccine; PPSV13, 13-valent pneumococcal polysaccharide vaccine.

References: