Elsevier

Vaccine

Volume 31, Issue 35, 2 August 2013, Pages 3585-3593
Vaccine

Immunogenicity and safety of a 13-valent pneumococcal conjugate vaccine in adults 70 years of age and older previously vaccinated with 23-valent pneumococcal polysaccharide vaccine

https://doi.org/10.1016/j.vaccine.2013.05.010Get rights and content
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Highlights

  • Free polysaccharide pneumococcal vaccine is generally recommended for older adults.

  • Conjugate and free polysaccharide vaccines were compared in pre-immunized adults.

  • Conjugate responses were significantly greater for majority of serotypes.

  • Conjugate vaccine did not negatively influence response to follow-on dose at 1 year.

  • Free polysaccharide vaccine diminished response to follow-on conjugate at 1 year.

Abstract

Background

The currently recommended single dose of the 23-valent pneumococcal free polysaccharide vaccine (PPSV23) for adults 65 years of age and older does not provide extended protection into older age. This reflects a significant unmet medical need for alternative strategies to protect older adults against pneumococcal infection, which may be met by the 13-valent polysaccharide conjugate vaccine (PCV13).

Methods

We performed a randomized, modified double-blind trial in 936 adults aged 70 years and older who had previously received PPSV23 at least 5 years before study entry and were now vaccinated with PCV13 or PPSV23. At 1 year after enrollment, all subjects received a follow-on dose of PCV13. Anti-pneumococcal opsonophagocytic activity (OPA) titers were measured before and at 1 month after each vaccination.

Results

Following the enrollment vaccination, OPA titers were significantly greater in the PCV13 group compared to the PPSV23 group for 10 of the 12 serotypes common to both vaccines and to serotype 6A which is unique to PCV13. Responses were noninferior for the other 2 common serotypes. Responses to PCV13 given at 1 year were generally lower in the group that received PPSV23 at enrollment.

Conclusion

In adults aged 70 years and older previously vaccinated with PPSV23, PCV13 was significantly more immunogenic than PPSV23 for most of the common serotypes and for serotype 6A. The OPA responses after a follow-on dose of PCV13 one year later indicate that a prior dose of PPSV23, but not PCV13, diminishes the response to the subsequent administration of PCV13.

Abbreviations

ACIP
United States Advisory Committee on Immunization Practices
AE
adverse event
CI
confidence interval
CRM197
cross-reactive material 197
GMR
geometric mean ratio
GMT
geometric mean titer
ITP
idiopathic thrombocytopenic purpura
OPA
opsonophagocytic activity
PCV
pneumococcal polysaccharide conjugate vaccine
PCV13
13-valent pneumococcal conjugate vaccine
PPSV23
23-valent polysaccharide vaccine
RCDC
reverse cumulative distribution curve
SAE
serious adverse event

Keywords

Adults
Pneumococcal conjugate vaccine
PCV13

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