|Vical Incorporated H1 Influenza Vaccine Delivers Robust Preclinical Results With 100% Response|
|By Staff and Wire Reports|
|Tuesday, 30 June 2009 07:26|
Vical Incorporated, which researches and develops biopharmaceutical products based on our patented DNA delivery technologies for the prevention and treatment of serious or life-threatening diseases has announced that the Company's vaccine against A/H1N1 pandemic influenza (swine flu) produced robust immune responses well above the accepted protection threshold in 100% of vaccinated mice and rabbits after a standard 2 dose vaccine regimen.In addition, at least 75% of vaccinated animals achieved or exceeded the protection threshold after a single dose of vaccine. In 2 parallel animal studies, one in mice and one in rabbits, vaccine was administered on Day 0 and Day 21, a standard regimen for pandemic influenza vaccines. Sera collected on Day 21, after a single dose of vaccine, showed clear increases over baseline hemagglutination inhibition (HI) titers in 100% of the animals, and HI titers above the protection threshold in 88% of the mice and 75% of the rabbits. Sera collected on Day 35, 2 weeks after the second dose, showed HI titers well above the protection threshold in 100% of the animals, ranging from 320 to 2,560 (geometric mean titer = 987) in the mice, and from 640 to 2,560 (geometric mean titer = 1,522) in the rabbits.
The HI assay measures a vaccine's ability to prevent viruses from binding to cells, and HI titers of 40 or more are accepted as the threshold for potential protection against influenza viruses. The vaccine encoded H1 hemagglutinin from the swine-origin A/California/04/09 wild-type influenza virus. Vical ran the HI assay against the swine-origin A/California/07/09 x-179a reassortant influenza virus obtained from the CDC.