Sanofi Pasteur, the vaccines division of the sanofi-aventis Group (EURONEXT: SAN and NYSE: SNY), announced today an interim analysis of data from clinical trials of the U.S. licensed Influenza A (H1N1) 2009 Monovalent Vaccine in infants and children 6 months through 9 years of age. The data indicate the vaccine is immunogenic and that one dose may protect many children. However, the study suggests that two doses of vaccine will be required for optimal protection of children under the age of 10 years. This is consistent with the recommendations for seasonal influenza immunization in children of this age. Clinical trials are ongoing to evaluate the immunogenicity and safety in children following two doses of vaccine.
"According to the Centers for Disease Control and Prevention young children are among those of highest priority for immunization with the Influenza A (H1N1) 2009 Monovalent Vaccine, given the relatively high disease incidence and potential for transmission in this population," said Wayne Pisano, President and Chief Executive Officer of Sanofi Pasteur. "As the only company licensed in the U.S. to produce a pediatric influenza vaccine which is licensed for children as young as 6 months of age, it was the highest priority for Sanofi Pasteur to conduct clinical trials to evaluate the safety and immunogenicity of the pandemic vaccine in children to support decisions on vaccine administration."
This randomized, placebo-controlled, multicenter trial was conducted by Sanofi Pasteur to determine the immunogenicity and safety of the vaccine, given as a two-dose schedule, 21 days apart. A total of 474 children were enrolled in the trial in two age cohorts: 229 children 6 months through 35 months of age; and 245 children 3 years through 9 years of age. The trial evaluated two antigen doses: formulated as 7.5 mcg and 15 mcg hemagglutinin in each cohort (ClinicalTrials.gov registration number NCT00952419). The interim results reported today are the first data available from children under the age of 10 years. Previously, Sanofi Pasteur reported that 98 percent of adults 18 years through 64 years of age had an immune response considered protective following one 15 mcg dose of vaccine.
The clinical trial in children evaluated immune responses to Sanofi Pasteur's Influenza A (H1N1) 2009 Monovalent Vaccine compared with placebo, based on rates of seroprotection and seroconversion. Two doses of vaccine were administered, the second dose 21 days after the first. Immunogenicity was measured at day 21, just prior to administration of the second dose, and will be measured again 21 days after the second dose at day 42. In both age groups, immune responses 21 days after one dose of the 15 mcg vaccine satisfied the criteria for seroconversion. The criteria for seroprotection were not met with only one 15 mcg dose of vaccine in either age group. In this clinical trial 76 percent of children 3 years through 9 years of age and 50 percent of children 6 months through 35 months of age had immune responses considered seroprotective following one 15 mcg dose of vaccine. An antibody titer of 1:40 or greater is generally considered a marker of seroprotection. A lower rise in antibody titers following vaccination may minimize the occurrence of disease and its consequences but is not considered seroprotective. Final data from these clinical trials, following a second dose of vaccine, will provide additional information to guide recommendations on the optimal dosage, number of doses and schedule.
Adverse events are being monitored throughout the clinical trial and will continue for six months after the second dose of vaccine. No serious adverse events have been reported in the trial to date. Local reactions reported have been similar to those observed with the seasonal influenza vaccine.
Children's Colorado earns prestigious cardiomyopathy recognition