Sanofi Pasteur, the vaccines division of Sanofi (EURONEXT: SAN and NYSE: SNY), presented today an overview of Phase II and Phase III clinical trials for its investigational quadrivalent influenza vaccine (QIV). Three clinical trials have been conducted to evaluate the safety and the immune response to the quadrivalent influenza vaccine in children, adults and the elderly. All three studies demonstrated that the safety and immunogenicity profiles of QIV were similar to licensed Fluzone® (Influenza Virus Vaccine). The addition of a second influenza B strain in the vaccine afforded coverage against that strain with no corresponding negative impact on the immune response to the other influenza strains in the vaccine.
The data were presented at IDWeek™, the first joint meeting of the Infectious Disease Society of America (IDSA), the Society for Healthcare Epidemiology of America (SHEA), the HIV Medicine Association (HIVMA) and the Pediatric Infectious Diseases Society (PIDS). Sanofi Pasteur announced on October 18th that the U.S. Food and Drug Administration (FDA) accepted its supplemental Biologics License Application for the quadrivalent formulation of its Fluzone vaccine for full review. Sanofi Pasteur is seeking FDA licensure of Fluzone quadrivalent vaccine for active immunization of children and adults 6 months of age and older for the prevention of influenza disease caused by influenza virus subtypes A and types B contained in the vaccine.
"Rates of hospitalization and death from influenza B are higher than those seen with A(H1N1) and, overall, influenza B is a significant cause of absenteeism, clinic visits, hospitalizations and complications across all ages, but especially in children," said David Greenberg, M.D., Senior Director, U.S. Scientific and Medical Affairs, Sanofi Pasteur. "Since two lineages of influenza type B circulate each season, public health officials have been challenged to predict which B virus to include in the vaccine to achieve the greatest effectiveness against circulating influenza strains. Due to increased vaccine production capacity in the U.S. we now have the ability to produce quadrivalent influenza vaccine to help protect against both lineages of B influenza and potentially provide a greater public health benefit from influenza immunization."
The strains for each season's influenza vaccine are selected by the FDA, in consultation with global health authorities, from the strains anticipated to circulate in the approaching influenza season. Seasonal influenza vaccines contained only two strains (one strain of type A influenza and one strain of type B influenza) until 1978, when the decision was made to incorporate a second type A influenza strain in order to provide protection against the two different A strains that were co-circulating. From then until now, influenza vaccines have been trivalent to help protect against three stains of influenza virus (two of type A and one of type B). However, since the influenza B Victoria lineage re-emerged worldwide in 2001-2002, two influenza B strains (one each from the Victoria and Yamagata lineages) have co-circulated with varying prevalence, making it difficult to predict the next season's dominant B strain. In six of the past 12 seasons, the dominant circulating B strain was from the B-lineage not selected for the vaccine, and even in years where the correct B virus strain was selected for the vaccine, some influenza disease was caused by the B strain omitted from the vaccine likely reducing the overall vaccine effectiveness against circulating influenza viruses. Inclusion of both circulating B lineages is a public health measure that can help reduce cases of influenza disease that could be vaccine-preventable if the additional strain were in the vaccine.