LB-3. 13-valent Pneumococcal Conjugate Vaccine (PCV13) Enhances the Response to Subsequent PCV13 and 23-valent Pneumococcal Polysaccharide (PPSV23) Vaccinations in Adults 50 Years and Older
Session: Poster Abstract Session: Late Breaker Posters
Saturday, October 22, 2011
Room: Poster Hall B1
Background:  Prior studies have shown that administration of PPSV23 blunts the response to a subsequent PCV13 or PPSV23 vaccination. Repeated administration of PCV13 at several year intervals may allow for preservation of immunogenicity to vaccine serotypes over time in older adults but the immune responses to a 2nd PCV13 given several years after a 1st dose are not well defined.

 Methods: This follow up study included 405 adults 60 through 64 years of age who had received either PCV13 or PPSV23 on enrollment in the primary study. Three to four years later, subjects received either PCV13 or PPSV23, to create the following study groups (primary study/follow up study): PCV13/PCV13, PCV13/PPSV23, PPSV23/PPSV23. In addition, 214 subjects 50 through 59 years given PCV13 in the primary study received PCV13 in the follow up study. Immune responses one month after the 1st and 2nd vaccinations were assessed by an opsonophagocytic (OPA) functional assay.

 Results: In comparing the OPA GMTs following the 2nd vaccination with those following the 1st, among subjects 60 through 64 years in the PCV13/PCV13 group, OPA GMTs following the 2nd dose PCV13 were statistically significantly higher than GMTs following the 1st dose for 7 of the 13 serotypes and were non- inferior for the other serotypes. OPA GMTs after PCV13/PPSV23 compared to PCV 13 or PPSV23 alone were statistically significantly higher for 7 of 12 and 9 of 12 common serotypes, respectively, indicating  that prior PCV13 enhanced the responses to subsequent PPSV23.

In contrast, diminished responses were seen in the PPSV23/PPSV23 group, with significantly lower GMTs after the 2nd vaccination for 8 of 12 PPSV23 serotypes compared to a single dose of PPSV23. Among the 50 through 59 year old group (PCV13/PCV13), significantly higher GMTs were seen after the 2nd vaccination for 6 of the 13 serotypes.

 Conclusions: Administration of PCV13 enhances the OPA responses to a subsequent PCV13 or PPSV23 vaccination given three to four years later in adults 50 years and older. Administration of PPSV23 is associated with reduced responses to a subsequent PPSV23 administration.  These observations reflect the potential immunological benefit of PCV13 in adults.


Subject Category: I. Adult and Pediatric Vaccines

Lisa A. Jackson, MD, MPH1, Alejandra Gurtman, MD2, Martin van Cleeff, MD3, Kathrin U. Jansen, PhD2, Deepthi Jayawardene, MS4, Carmel Devlin2, Daniel A Scott, MD2, Emilio A. Emini, MD4, William Gruber, MD2 and Beate Schmoele-Thoma, MD5, (1)Group Health Research Institute, Seattle, WA, (2)Pfizer Inc, Pearl River, NY, (3)Cary Medical Research, Cary, NC, (4)Pfizer Inc, Collegeville, PA, (5)Pfizer Inc, Muensing-Ambach, Germany


L. A. Jackson, Pfizer: Grant Investigator and Scientific Advisor, Consulting fee, Grant recipient and travel support
Merck: Scientific Advisor, Consulting fee

A. Gurtman, pfizer: Employee and Shareholder, Salary

M. van Cleeff, None

K. U. Jansen, Pfizer: Employee and Shareholder, Salary

D. Jayawardene, Pfizer: Employee and Shareholder, Salary

C. Devlin, Pfizer: Employee and Shareholder, Salary

D. A. Scott, Pfizer: Employee and Shareholder, Salary

E. A. Emini, Pfizer: Employee and Shareholder, Salary

W. Gruber, Pfizer: Employee and Shareholder, Salary

B. Schmoele-Thoma, Pfizer: Employee, Salary

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