658. Safety, Tolerability, and Immunogenicity of 15-Valent Pneumococcal Conjugate Vaccine (PCV15) in Healthy Adults
Session: Poster Abstract Session: Pneumococcal Vaccines
Friday, October 21, 2011
Room: Poster Hall B1
Background: 

Implementation of 7-valent pneumococcal conjugate vaccine (PCV7) into childhood immunization schedule led to a significant decrease in invasive pneumococcal diseases in targeted population and unvaccinated adults. However, diseases caused by serotypes not included in Prevnar™ have emerged and new vaccines with broader serotype coverage are needed. A 15-valent pneumococcal conjugate vaccine (PCV15) containing the same 7 serotypes in PCV7 plus 8 additional serotypes (1, 3, 5, 6A, 7F, 19A, 22F, 33F) was developed and first evaluated in 60 healthy adults aged 18 to 45 years prior to being evaluated in children.

Methods: Sixty adults received a single dose of PCV15 or PCV7.  Injection site and systemic adverse events (AEs) were collected for 14 days postvaccination and serious AEs were collected for 30 days postvaccination.  Laboratory abnormalities were evaluated prior to and 14 days postvaccination. Serotype-specific IgG and OPA responses were measured immediately prior and 30 days postvaccination. 

Results: 

Incidences of local and systemic AEs were comparable between vaccine groups although numerically higher among recipients of PCV15 than PCV7 for local erythema (33% versus 13.5%) and swelling (50% versus 23.3%) as well as myalgia (63.3% versus 36.7%). Majority of reported events, irrespective of treatment, were transient and of mild to moderate intensity.  No clinically significant differences were observed when comparing duration and severity of AEs.  No laboratory abnormalities, vaccine-related SAEs or discontinuations from the study due to AEs were reported postvaccination. IgG concentrations for the shared serotypes significantly increased postvaccination at comparable levels between recipients of PCV15 (7 to 28-fold) and PCV7 (5 to 26-fold). Increases for 8 serotypes contained in PCV15 but not in Prevnar® were 3 to 13-fold among recipients of PCV15 and slightly increased only for serotypes 6A and 19A among recipients of PCV7. Similar findings were observed when comparing OPA titers between the 2 groups

Conclusion: PCV15 displays an acceptable safety profile and induces IgG and OPA responses to all serotypes included in the vaccine.


Subject Category: I. Adult and Pediatric Vaccines

Luwy Musey, MD, Merck & Co., Inc, Blue Bell, PA

Disclosures:

L. Musey, Merck& Co., Inc: 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.