Inovio Biomedical Corporation (NYSE Amex:INO), a leader in DNA vaccine design, development and delivery, announced today that a combination of its synthetic consensus (SynConTM) H1N1 influenza vaccine candidates achieved protective antibody responses against the novel pandemic influenza A/H1N1 (2009) in 100% of tested ferrets. The ferret model is widely considered to be the most representative of human influenza; achieving in ferrets a level of antibody titers commonly associated with protection in humans is a critical milestone in influenza vaccine development. Dr. Niranjan Y. Sardesai, Inovio’s Sr. VP, Research and Development, presented this data at the Vaccine 3rd Global Congress in Singapore in a presentation entitled, “Development of Universal SynCon™ DNA Vaccines for Pandemic and Seasonal Flu.”
Following promising results in mice and pigs with SynCon™ H1N1 DNA vaccine candidates, as referenced in previous news releases, in this study Inovio scientists immunized ferrets with a formulation of H1N1 DNA vaccine candidates. They then tested the ferrets’ serum for hemagglutination inhibition (HI) responses against one of the 2009 pandemic H1N1 strains, A/H1N1/Mexico/InDRE4487/2009.
HI measurements from the blood of vaccinated animals are used to assess the generation of protective antibody responses. Generating an antibody titer of 1:20 is generally regarded as a positive vaccine response, with a titer of 1:40 or higher in the blood of vaccinated subjects generally associated with protection against influenza in humans.
In this experiment, a single vaccination showed induction of positive immune responses in 78% (7 of 9) of ferrets, with a mean HI titer of 1:42. After two booster shots, 100% of immunized ferrets had HI titers greater than 1:40, with the mean titer rising to 1:390.