Immunogenicity and safety of the quadrivalent meningococcal serogroups A, C, W-135 and Y tetanus toxoid conjugate vaccine (MenACWY-TT) in 2-10-year-old children: results of an open, randomised, controlled study.

UNLABELLED: In Europe, the introduction of monovalent meningococcal serogroup C (MenC) conjugate vaccines has resulted in a significant decline in MenC invasive disease. However, given the potential for strain evolution and increasing travel to areas of high endemicity, protection against additional serogroups is needed. In this study, the immunogenicity, measured by a serum bactericidal activity assay using rabbit complement (rSBA), and the safety of a quadrivalent meningococcal serogroups A, C, W-135 and Y tetanus toxoid conjugate vaccine (MenACWY-TT) were compared to that of a licensed monovalent MenC conjugate vaccine (MenC-CRM197) in children 2-10 years of age. Children were randomised (3:1) to receive a single dose of either MenACWY-TT or MenC-CRM197. Non-inferiority of the immunogenicity of MenACWY-TT versus MenC-CRM197 in terms of rSBA-MenC vaccine response was demonstrated. Exploratory analyses suggested that rSBA-MenC geometric mean titres adjusted for pre-vaccination titres were lower in children vaccinated with MenACWY-TT compared to MenC-CRM197. Nevertheless, at 1 month post-vaccination, ≥99.3 % of the children who received MenACWY-TT had rSBA titres ≥1:128 for each of the four vaccine serogroups, which is the more conservative correlate of protection. The reactogenicity and safety profile of MenACWY-TT was clinically acceptable and no serious adverse events considered related to vaccination were reported throughout the study. CONCLUSION: When administered to European school-age children, MenACWY-TT has a clinically acceptable safety profile and, when compared with MenC-CRM197, the potential to broaden protection against meningococcal disease caused by serogroups A, W-135 and Y while maintaining protection against MenC. This study has been registered at www.clinicaltrials.gov NCT00674583.

Immune memory to hepatitis B virus in 4-9-year old children vaccinated in infancy with four doses of hexavalent DTPa-HBV-IPV/Hib vaccine.

The combined hexavalent diphtheria-tetanus-acellular pertussis-hepatitis B-inactivated polio Haemophilus influenzae type b (DTPa-HBV-IPV/Hib) vaccine produces similar hepatitis B responses as the HBV monovalent vaccine. Booster vaccination of immunocompetent individuals primed against hepatitis B in infancy is currently not recommended. We investigated persisting immunity to hepatitis B in 4-6 (Study A; 106745) and 7-9 (Study B; 106744) year-old children primed in infancy and boosted in the second year of life with DTPa-HBV-IPV/Hib. Immunity was assessed by measuring persisting anti-HBs antibodies and evaluating the response to a challenge dose of HBV vaccine. At 4-6 years of age 86.0% of 186 subjects had persisting anti-HBs > or =10 mIU/ml increasing to 98.4% after the challenge. At 7-9 years of age, 78.0% of 186 subjects continued to have anti-HBs antibody concentrations > or =10 mIU/ml, increasing to 98.9% after the challenge. In both studies anti-HBs antibody GMC rose >80-fold. An anamnestic response to the HBV challenge was observed in 95.7% and 98.9% of subjects in Studies A and B, respectively. In both studies, 87% of 38 subjects with initially undetectable circulating anti-HBs antibodies (>3.3 IU/ml) achieved the 10 mIU/ml threshold after challenge; > or =97.0% of subjects with detectable antibodies before the challenge at least quadrupled their concentration. Post-vaccination anti-HBs concentrations were directly related to persisting antibody concentrations and the concentrations achieved after the booster dose in the second year of life. The HBV vaccine challenge dose was well tolerated. These studies show that primary and booster vaccination with combined DTPa-HBV-IPV/Hib (Infanrix hexa) induces sustained immune memory against hepatitis B up to age 9 years.

Immunogenicity and safety assessments after one and two doses of a refrigerator-stable tetravalent measles-mumps-rubella-varicella vaccine in healthy children during the second year of life.

BACKGROUND: Measles, mumps, and rubella (MMR) and varicella (V) vaccines are often coadministered at 1 clinic visit. This study (104389/NCT00127023) was undertaken to assess the immunogenicity and safety of a new refrigerator-stable tetravalent MMRV vaccine after 1 dose and after 2 doses administered during the second year of life. METHODS: Nine hundred seventy healthy children aged 10-21 months received 2 doses of MMRV vaccine (Priorix-Tetra; GlaxoSmithKline Biologicals, Rixensart, Belgium) 42 days apart (MMRV group; N = 732) or 1 dose of MMR vaccine (Priorix) coadministered with varicella vaccine (Varilrix) followed by a second dose of only MMR vaccine 42 days later (MMR + V group; N = 238). RESULTS: Observed seroconversion rates for measles, mumps, rubella, and varicella antibodies 42 days postdose 1 were 94.5%, 96.1%, 99.7%, 95.5% in the MMRV group and 93.4%, 93.6%, 98.1%, 95.6% in the MMR + V group. Respective seroconversion rates postdose 2 were 98.3%, 99.4%, 99.7%, 99.7% in the MMRV group and 97.6%, 99.5%, 100%, 97.5% in the MMR + V group. Observed antimeasles and antimumps geometric mean titers (GMTs) were higher after each dose in the MMRV group than in the MMR + V group. Antivaricella GMT increased 21-fold in the MMRV group postdose 2, and was markedly higher than in the MMR + V group who did not receive a second dose of varicella (1903.3 and 80.3 dilution, respectively). Both vaccine regimens were generally well-tolerated in terms of local reactions, fever >39.5 degrees C, and vaccine-related rashes. CONCLUSIONS: Both after 1 dose and after 2 doses, the MMRV vaccine was at least as immunogenic as concomitant MMR and varicella vaccination suggesting that it could be suitable for use according to current vaccination schedules.

Immunogenicity and safety of a tetravalent measles-mumps-rubella-varicella vaccine co-administered with a booster dose of a combined diphtheria-tetanus-acellular pertussis-hepatitis B-inactivated poliovirus-Haemophilus influenzae type b conjugate vaccine in healthy children aged 12-23 months.

This study was undertaken to assess the co-administration of an experimental measles-mumps-rubella-varicella vaccine (MMRV, GlaxoSmithKline Biologicals) with a combined diphtheria-tetanus-acellular pertussis-hepatitis B-inactivated poliovirus-Haemophilus influenzae type b conjugate (DTPa-HBV-IPV/Hib) vaccine in healthy children. Healthy children aged 12-23 months (N = 451) were randomised to one of three parallel groups to receive one dose of MMRV vaccine co-administered with a booster dose of DTPa-HBV-IPV/Hib vaccine (co-administration group), or one dose of MMRV vaccine alone (MMRV group), or a booster dose of DTPa-HBV-IPV/Hib vaccine alone (DTPa-HBV-IPV/Hib group). No differences in seroconversion rates for measles (>95%), mumps (>80%), rubella (>99%) and varicella (>98%) were seen between the co-administration group and the MMRV group. No differences in geometric mean titres (GMTs) were observed between the two groups with the exception of anti-measles titres, which were observed to be higher in the MMRV group than in the co-administration group (4,419.2 vs. 3,441.8 mIU/ml respectively). Immune response to the booster dose of DTPa-HBV-IPV/Hib vaccine was observed to be similar in the co-administration group and the DTPa-HBV-IPV/Hib group. Co-administration of the MMRV vaccine with a booster dose of DTPa-HBV-IPV/Hib vaccine was well-tolerated and did not exacerbate the reactogenicity profile of either vaccine. In summary, GlaxoSmithKline Biologicals' experimental MMRV vaccine was immunogenic and well-tolerated when administered with a booster dose of DTPa-HBV-IPV/Hib vaccine during the second year of life. The ability to co-administer the MMRV vaccine at the same time as other routine childhood immunisation vaccines could increase compliance with varicella vaccination in countries where this vaccine is already recommended and may facilitate implementation of varicella vaccination elsewhere.