In the recent study, Vaxart tested the ND1 vaccine using oral administration to ferrets, widely recognized as the most predictive animal model for influenza research. Researchers administered vaccine at the start of the study and at 4 weeks. At 8 weeks, researchers measured antibody responses, then monitored survival following direct nasal exposure of 10 times the median lethal dose of H5N1 avian influenza virus. Seventy-five percent (6 of 8) of oral vaccinated ferrets developed antibody levels of 1:200 or greater, survived the challenge and were healthy as demonstrated by weight gain after challenge, while all 12 control ferrets either died (67 percent) or became very ill (33 percent). These results, if confirmed in human immunogenicity studies, compare well to the approved, injectable avian flu vaccine that achieved protective antibody levels in 45 percent of human subjects.
In a previous study conducted in mice, 6 of 6 mice vaccinated orally with ND1 survived H5N1 avian flu challenge, while 8 of 8 unvaccinated mice died. Based on these results, Vaxart plans to proceed to an investigational new drug application (IND) and begin clinical studies of the avian flu vaccine in 2009. The company is also developing an annual flu vaccine.
"To date, efforts to develop a broadly-applicable oral vaccine platform have not been successful, but the advantages of a modular approach for vaccine development are compelling, particularly for influenza," said Mark Backer, PhD, Vaxart CEO. "We can provide a vaccine that matches a new outbreak strain months faster than current approaches."
"These results are encouraging. An oral vaccine for pandemic flu would
be a great help in rapid distributi
|SOURCE Vaxart Inc.|
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