634. Persistence of Bactericidal Antibodies and Boosting after Vaccination with Menveo in Adolescents Enrolled in Phase II and III Clinical Studies
Session: Poster Abstract Session: Pediatric Vaccines
Friday, October 21, 2011
Room: Poster Hall B1
Background: Menveo® is a quadrivalent meningococcal conjugate vaccine against serogroups A, C, W-135 and Y approved in the US for use in persons 2 to 55 years of age. In October 2010, a booster dose was recommended by ACIP for adolescents who had previously received meningococcal vaccination. We present an overview of immunogenicity at up to 5 years after vaccination and available booster data among previously vaccinated adolescents.

Methods: Findings of two studies were reviewed to provide an overview of antibody persistence after Menveo compared with two licensed meningococcal vaccines (Menactra® and Menomune®, 3 and 5 years postvaccination, respectively). Immune responses and reactogenicity were evaluated after a booster dose of Menveo either 3 years after initial vaccination with Menveo or Menactra, or 5 years after initial vaccination with Menveo or Menomune. Immunogenicity was assessed via serum bactericidal assays with exogenous human complement source (hSBA).

Results: At 3 years postvaccination, antibody persistence in terms of hSBA titers ≥ 8, was significantly higher in subjects vaccinated 3 years earlier with Menveo (n ~ 287) than Menactra (n~ 200) for serogroups W-135 (p <0.01) and Y (p <0.01) and similar for serogroups A and C. Among those receiving a booster dose of Menveo 3 years after either Menveo or Menactra, ~99% achieved an hSBA titer ≥ 8. Reactogenicity profiles were similar after booster dose when compared with original vaccination and no serious adverse events were reported. At 5 years postvaccination, over 70% of subjects from the phase II study (n = 50) had an hSBA ≥ 1:8 to each of serogroups C, W and Y.

Conclusion: Analysis across separate phase II and III studies after Menveo vaccination support persistence of bactericidal antibodies to at least 5 years post-vaccination. Robust booster responses to Menveo after either original vaccination with Menveo or Menactra are not accompanied by increased reactogenicity or other safety concerns.


Subject Category: I. Adult and Pediatric Vaccines

Lisa A. Jackson, MD, MPH, Center for Health Studies, Seattle, WA, Roger Baxter, MD, Kaiser Permanente Vaccine Study Center, Oakland, CA, Christopher J. Gill, MD, Novartis Vaccines and Diagnostics, Cambridge, MA, Tatjana Odrljin, MD, Novartis Vaccines & Diagnostics, Cambridge, MA and Peter Dull, MD, Clinical Development, Novartis Vaccines and Diagnostics, Cambridge, MA

Disclosures:

L. A. Jackson, None

R. Baxter, None

C. J. Gill, Novartis Vaccines & Diagnostics: Employee, Salary

T. Odrljin, Novartis Vaccines & Diagnostics: Employee, Salary

P. Dull, Novartis Vaccines & Diagnostics: Employee, Salary

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