Phase 2 study of H5N1 avian influenza pandemic vaccine (H5N1 vaccine)

Medicago reported positive interim results from a Phase 2 trial with its H5N1 avian influenza Virus-Like Particle (VLP) vaccine candidate (H5N1 vaccine). The study enrolled 135 healthy volunteers who were immunized with Medicago’s vaccine at 3 dosage levels to determine the optimal dose. In those vaccinated in the 18-49 age group at the 20 microgram dosage level, 82% of immunized subjects developed an immune response against the H5N1 virus after the second immunization, 65% of subjects had a four-fold increase in HI titers from baseline and  65% of subjects had seroprotective antibody titers. All subjects tested negative for antibodies to the H5N1 A/Indonesia strain before vaccination and no response was observed among individuals who received a placebo. These data show that Medicago’s H5N1 vaccine induces a robust hemagglutination inhibition (HAI) antibody response against the H5N1 vaccine strain. The H5N1 vaccine also induced the production of antibodies that react with multiple strains of H5N1 Avian Influenza indicating the potential for cross-protection of Medicago’s vaccines.

Medicago’s H5N1 VLP vaccine candidate was formulated to protect against the Indonesian influenza virus. VLPs are designed to look like a virus, allowing them to be recognized readily by the body’s immune system, however, they lack the core genetic material making them non-infectious and unable to replicate.

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