Pandemic flu vaccine provides 100% protection in mice at low doses

Quebec City, QC – Biotechnology company Medicago says that, in a preclinical study, low doses of its H5N1 avian influenza virus-like particle (VLP) vaccine provided 100% protection in mice against a lethal challenge of live H5N1 viruses. In addition, the study demonstrated that Medicago’s vaccine has the ability to recognize and kill an H5N1 strain that is different from the one used to design the vaccine.

The study was conducted in Lyon, France at the P4 Laboratory Jean Merieux – Institut National de la Sante et de la Recherche Medicale (INSERM), a high-security research centre for studying highly pathogenic viruses. In this study, mice were vaccinated with a range of doses of the company’s vaccine made from an Indonesian strain of H5N1 avian influenza. The mice were then challenged with a different live H5N1 strain from Turkey. Results demonstrated that mice vaccinated with the vaccine were fully protected from illness and subsequent death even at the low dose of 0.5 microgram. During the experiment, 100% of the vaccinated mice survived, while 60% of the control group died. The study was performed in collaboration with Dr Herve Raoul, director of the P4 Laboratory Jean Mrieux-INSERM, Dr Vincent Lotteau, immunologist at INSERM, Professor Bruno Lina from Lyon University and Dr Eric Quemeneur, head of biochemistry and nuclear toxicology at the French Atomic Energy Commission.

“I’m very pleased with these results and I take great pride in what our team and our collaborators have been able to accomplish,” said Andy Sheldon, Medicago’s president and CEO. “The successful completion of this first lethal challenge study is an important step in moving our H5N1 VLP vaccine towards human clinical studies. Results from this preclinical study will be included in a clinical trial application currently targeted for the fourth quarter of 2008 and human trials are expected to commence following clearance by Health Canada.”

“A major hurdle with development of pandemic flu vaccines has been the mutation of the H5N1 virus over time. As a result, cross-protection, rapid development and production are key components in the successful development of these vaccines,” said Nathalie Landry, Medicago’s vice president product development. “This is the first demonstration that our VLP vaccine can protect against infection with a live deadly virus and provide cross-protection among different strains of H5N1 in circulation. These results further demonstrate the potential of our manufacturing technology and vaccine in addressing a significant global health problem.”