Medicago reports positive interim results for H7N9 pre-clinical trial
The trial found that three micrograms of the H7 vaccine administered with and without an adjuvant induced high antibody titers following one vaccine dose. Medicago developed the plant-made H7N9 vaccine for the H7N9 influenza virus, which caused 133 reported cases and 37 deaths in China as of May 29.
"These results are very significant as there is a general concern that H7 vaccines will be of low immunogenicity in humans should a pandemic be declared," Andy Sheldon, the president and CEO of Medicago, said. "However, our results indicate that our plant-based H7 vaccine is able to generate a high immune response in animal models. To our knowledge, this is the first report of preclinical results for an H7 vaccine developed for the recent H7N9 virus, further demonstrating that Medicago is well positioned to be a first responder in the face of a pandemic."
Medicago developed the first vaccine lots for H7N9 on May 9, just 19 days after Medicago received the DNA genes from the GISAID EpiFlu Database. The emerging H7N9 strain is a concern to the vaccine community as it is only a few mutations away from being completely transmissible to humans.
"This is an important first step in our H7N9 program," Nathalie Landry, the vice president of product development at Medicago, said. "Previous H7N3 and H7N1 avian vaccines derived from eggs have been tested in humans without achieving significant antibody levels even at doses as high as 2x90 micrograms or 2x24 micrograms mixed with alum. Previous vaccines from other technologies also induced very low antibody levels in the mouse model, whereas Medicago's results indicate that our H7 vaccine developed for the emerging H7N9 strain elicits a solid antibody response in mice after a single dose. Results from challenge studies will be available in the coming month."
Medicago develops VLP vaccines using a transient expression system that produces recombinant vaccine antigens in plants, allowing for the development of a vaccine for testing approximately one month after receiving a pandemic strain's genetic sequence.