Medicago announces positive results for H1N1 pandemic vaccine candidate

Jul 31 2009

Medicago today announced that it has achieved additional positive results with its vaccine candidate for the Influenza A (H1N1) virus, also known as Swine flu. Results showed that a single dose of 5 micrograms induced a positive immune response against a new emerging strain of this virus in 100% of vaccinated animals.

Medicago's H1N1 VLP vaccine was formulated to protect against the influenza A/California/04/09 virus ("California/04"), which was one of the original viral strains selected by the WHO for vaccine manufacturers. The Company previously reported data from an initial study in mice where its novel vaccine achieved a positive immune response in 100% of the animals vaccinated against the California/04 virus. In a continuation of this study, Medicago tested the immune response of its H1N1 vaccine against the California/07 virus, a more current and mutated strain and showed positive immune response after a single dose of 5 micrograms. The challenge of current pandemic influenza vaccines is they have to match the circulating strain in order to be effective.

"We have already demonstrated the speed of our technology by producing an H1N1 vaccine candidate and initiating animal testing while other vaccine manufacturers were still waiting for a seed strain from the WHO. These additional data expand upon the results we announced in June and support our belief that our influenza vaccines are also capable of providing protection against different circulating viral strains," said Andy Sheldon, President and CEO of Medicago. "Unlike current vaccine manufacturers that have experienced difficulties producing a pandemic candidate for H1N1, our H1N1 vaccine candidate was well expressed in our plant-based system and has produced good yields."

Vaccine makers currently developing vaccine candidates for the pandemic swine flu using egg-based and cell culture technologies have advised the WHO that the influenza seed strain used to produce their new vaccine is not growing well and therefore giving poor antigen yields. The yield is approximately 25-50% of that vaccine makers typically get for seasonal flu vaccine production. The WHO recently made a new set of seed strains using new viral isolates, such as the California/07, in hopes of increasing the vaccine yield. Medicago's vaccine is produced using its VLP technology that does not require a virus and therefore does not rely on the ability of a viral strain to grow.