665. A Phase 3, Randomized, Active-Controlled Trial to Evaluate the Safety, Tolerability, and Immunogenicity of  Sequential Administration of 13-Valent Pneumococcal Conjugate Vaccine (PCV13) and 23-Valent Pneumococcal Polysaccharide Vaccine (PPSV23) Administered at 1-year Intervals in PPSV23- naïve Adults 60-64 Years of Age
Session: Poster Abstract Session: Pneumococcal Vaccines
Friday, October 21, 2011
Room: Poster Hall B1
Background: When considering the use of both PCV13 and PPSV23, is there an optimal sequence for vaccination in PPSV23- naïve adults? This trial’s primary objectives were to examine noninferiority of immune responses to PCV13 boosted 1 year later with PPSV23 (PCV13/PPSV23) vs. the initial dose of PPSV23, and noninferiority of immune responses in adults receiving PCV13/PPSV23 vs. PPSV23/PCV13.

Methods: 720 adults aged 60–64 years were randomized in a 3:5:4 ratio to receive PCV13/PCV13 (n=180), PCV13/PPSV23 (n=302) or PPSV23/PCV13 (n=238) one year apart. Blood samples were taken for immunogenicity testing (opsonophagocytic assay (OPA)) before and ~1 month after each vaccination. Local and systemic reactions were monitored for 2 weeks after each vaccination by e-diary. Adverse events were collected at each visit and by phone contact 6 months after each vaccination. The primary immunological comparisons were made using logarithmically-transformed OPA titers to the 12 common serotypes.  

Results: For PCV13/PPSV23 vs. PPSV23, noninferiority was demonstrated for all serotypes and PCV13/PPSV23 elicited significantly greater OPA titers for 6 of 12 common serotypes. For PCV13/PPSV23 vs. PPSV23/PCV13, noninferiority was met for all serotypes; OPA titers were significantly greater for 11 of 12 common serotypes in adults who received PCV13/PPSV23 vs. PPSV23/PCV13.The frequency and severity of local reactions were generally similar after initial vaccination with PCV13 or PPSV23, and after a dose of PCV13 one year after PCV13 or PPSV23. Local reactions were more common and more severe when PPSV23 followed PCV13 at one year. Systemic reactions were generally similar across all comparisons. No SAEs were considered vaccine related.

Conclusion: Initial use of PCV13 permits the subsequent administration of PPSV23 as PCV13/PPSV23 results in OPA responses that are noninferior for all, and statistically superior for a number of the serotypes. In contrast, PPSV23 administration establishes an immunologic state that results in a diminished response to subsequent administration of PCV13. Local reactions were increased when PPSV23 was given after PCV13. If both vaccines are to be administered to an older adult population naïve to PPSV23, PCV13 should be given first.

Subject Category: I. Adult and Pediatric Vaccines

Richard N Greenberg, MD1, Alejandra Gurtman, MD2, Robert Frenck, MD3, Cynthia B. Strout, MD4, Kathrin U. Jansen, PhD2, Deepthi Jayawardene, MS5, Daniel A Scott, MD2, Emilio A. Emini, MD2, William Gruber, MD2 and Beate Schmoele-Thoma, MD6, (1)University of Utah, Salt Lake City, UT, (2)Pfizer Vaccines Research, Pfizer Inc, Pearl River, NY, (3)Cincinnati Children's Hospital Medical Center, Cincinnati, OH, (4)Coastal Carolina Research Center, Mount Pleasant, SC, (5)Pfizer, Inc, Collegeville, PA, (6)Pfizer, Inc, Berlin, Germany


R. N. Greenberg, Pfizer: Investigator, Contract with the Univ. of Kentucky
PaxVax: Investigator, Contract with the Univ. of Kentucky
Bavarian Nordic: Investigator, Contract with the Univ. of Kentucky
Virxsys: Investigator, Contract with the Univ. of Kentucky

A. Gurtman, pfizer: Employee and Shareholder, Salary

R. Frenck, Pfizer: Investigator, Research support

C. B. Strout, pfizer: Investigator, Research support
merck: Investigator, Research support
dynport: Investigator, Research support
Bayer: Investigator, Research support

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

D. Jayawardene, 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 and Shareholder, Salary

Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 20 with the exception of research findings presented at IDSA press conferences.