Influence of initial vaccination with 13-valent pneumococcal conjugate vaccine or 23-valent pneumococcal polysaccharide vaccine on anti-pneumococcal responses following subsequent pneumococcal vaccination in adults 50 years and older

AbstractBackgroundUnlike free polysaccharide vaccines, pneumococcal polysaccharide conjugate vaccines (PCVs) induce a T cell-dependent immune response and have the potential to provide an extended duration of protection with repeated vaccinations.MethodsThis was an extension of a previous study in pneumococcal vaccine-naïve adults aged 50–64 years in which adults 60–64 years of age were given 13-valent PCV (PCV13) or 23-valent pneumococcal polysaccharide vaccine (PPSV23) and adults aged 50–59 were given PCV13. In this follow up study conducted about 4 years later, the 60–64 year olds initially given PCV13 received PCV13 or PPSV23, and those initially given PPSV23 received another PPSV23. All adults aged 50–59 years were re-vaccinated with PCV13. Anti-pneumococcal opsonophagocytic activity (OPA) titers were measured before and 1 month after vaccination.ResultsA second PCV13 given about 4 years after a first vaccination induced OPA titers that were significantly higher than those following the initial vaccination for 7 of 13 serotypes in the older group, and 6 of 13 serotypes in the younger group, and responses to the remaining serotypes were largely non-inferior. In contrast, OPA titers following revaccination with PPSV23 were statistically significantly lower for 9 of the 13 serotypes, and non-inferior for the remaining serotypes, when compared to the responses to the first PPSV23. OPA titers in the older adults who received PPSV23 after initial PCV13 were significantly higher than those following a first PPSV23 for 10 of the 13 serotypes.ConclusionIn adults 50 to 64 years of age, initial vaccination with PCV13 establishes an immune state that results in recall anti-pneumococcal responses upon subsequent vaccination with either conjugated or free polysaccharide vaccine. In contrast, initial vaccination with PPSV23 results in an immune state in which subsequent PPSV23 administration yields generally lower responses compared with the initial responses

Vaccine-Induced Immunity in Baboons by Using DNA and Replication-Incompetent Adenovirus Type 5 Vectors Expressing a Human Immunodeficiency Virus Type 1 gag Gene

This is the published version. Copyright 2003 American Society for Microbiology.The cellular immunogenicity of formulated plasmid DNA and replication-defective human adenovirus serotype 5 (Ad5) vaccine vectors expressing a codon-optimized human immunodeficiency virus type 1 gag gene was examined in baboons. The Ad5 vaccine was capable of inducing consistently strong, long-lived CD8+-biased T-cell responses and in vitro cytotoxic activities. The DNA vaccine-elicited immune responses were weaker than those elicited by the Ad5 vaccine and highly variable; formulation with chemical adjuvants led to moderate increases in the levels of Gag-specific T cells. Increasing the DNA-primed responses with booster doses of either Ad5 or modified vaccinia virus Ankara vaccines suggests a difference in the relative levels of cytotoxic and helper responses. The implications of these results are discussed

Immunogenicity and safety of 13-valent pneumococcal conjugate vaccine in Mexico

OBJECTIVE: To assess the safety and immune responses induced by a 13-valent pneumococcal conjugate vaccine (PCV13) after immunization of infants in Mexico. METHODS: PCV13 was given with other routine childhood vaccinations to 225 infants in Mexico at ages 2, 4, 6, and 12 months. RESULTS: The proportions of subjects achieving immunoglobulin G (IgG) concentrations ≥0.35 µg/mL after the infant series and toddler dose were ≥93.1% and ≥96.7%, respectively, for all 13 serotypes. The serotype-specific pneumococcal IgG geometric mean concentrations after the infant series and toddler dose ranged from 1.18 to 9.13 µg/mL and from 1.62 to 15.41 µg/mL, respectively. The most common local reaction and systemic event after each dose were tenderness and irritability, respectively. Most fever was mild; no fever >40.0°C (i.e., severe) was reported. One subject withdrew because of Kawasaki disease 5 days after the first dose of vaccines, but this condition was not considered related to PCV13. CONCLUSIONS: Overall, PCV13 administered with routine pediatric vaccines was immunogenic and safe in healthy infants in Mexico

13-Valent pneumococcal conjugate vaccine (PCV13) in children partially immunized with 7-valent pneumococcal conjugate vaccine (PCV7): A phase 3, open-label trial

Background: As 13-valent pneumococcal conjugate vaccine (PCV13) is introduced, children who began vaccination with 7-valent pneumococcal conjugate vaccine (PCV7) may complete their vaccination with PCV13. This open-label phase 3 study evaluated immunogenicity and safety of PCV13 in Swedish infants and toddlers previously given 1 or 2 doses of PCV7 during infancy. Methods: Healthy infants previously given PCV7 at ages 3 months (group 1; n = 118) or 3 and 5 months (group 2; n = 116) received PCV13 at ages 5 (group 1) and 12 months (both groups). IgG responses were assessed 1 month after each PCV13 dose and before the 12-month dose. Local reactions and systemic events were collected for 7 days postvaccination. Other adverse events were also collected. Results: Post-5-month dose, IgG geometric mean concentrations (GMCs) in group 1 were 1.56-4.70 mu g/ml for most PCV7 serotypes except 6B (0.40 mu g/ml) and 23F (0.57 mu g/ml) and 0.72-1.88 mu g/ml for most of the 6 additional serotypes, except 6A (0.28 mu g/ml). Post-12-month dose, IgG GMCs for the PCV7 serotypes were 2.93-9.63 mu g/ml (group 1) and 3.33-9.30 mu g/ml (group 2); and for the 6 additional serotypes, 1.85-14.65 mu g/ml (group 1) and 1.34-13.16 mu g/ml (group 2). GMCs increased by >4-fold in both groups from pre- to post-12-month dose. Proportions of subjects in group 1 with pneumococcal serotype-specific IgG concentrations >= 0.35 mu g/ml (WHO-designated postprimary reference antibody level) post-5-month dose were 92.2-99.1% for most PCV7 serotypes except 6B (53.0%) and 23F (62.6%) and 80.9-100.0% for most of the 6 additional serotypes except 6A (36.8%). Local reactions and fever were mostly mild or moderate. Conclusions: PCV13 was immunogenic and safe in infants and toddlers previously partially immunized with PCV7. Even a single dose in an infant or toddler induces an immune response to the 6 additional serotypes. (C) 2013 Published by Elsevier Ltd