VaxInnate, a privately-held biotechnology company, has begun patient enrolment in a Phase 1 clinical trial evaluating its H5 vaccine candidate, VAX161, for the prevention of pandemic avian influenza or bird flu.

VAX161 is a recombinant fusion protein which consists of the globular head domain of the haemagglutinin antigen (HA) of influenza A HA5 Indonesia fused to Salmonella typhimurium flagellin type 2, a toll-like receptor 5 ligand.

VaxInnate chief medical officer, David Taylor, said the objective of this study is to optimise the dose, based on the immunogenicity and safety of VAX161.

"We believe our vaccine candidate has the potential to be a highly effective and much-needed vaccine for pandemic avian flu," Taylor added.

"Our vaccine candidate has the potential to be a highly effective and much-needed vaccine for pandemic avian flu."

The trial, which includes 250 healthy adults aged between 18 and 49 years, is being conducted under VaxInnate’s contract with the Biomedical Advanced Research and Development Authority, part of the US Department of Health and Human Services.

The safety and immunogenicity of two doses of VAX161 given by intramuscular injection three weeks apart at six dose levels ranging from 1µg to 12µg will be evaluated.

The company expects the results of the study, which will confirm the appropriate dose of VAX161 for further development, late in 2012.

Casey Johnson, DO of Johnson County Clin-Trial in Lenexa, Kansas, and principal investigator, said: "We believe VaxInnate’s approach to vaccine development holds a great deal of promise for avian flu and look forward to learning more about the potential of VAX161 in this clinical trial."

Under the supervision of principal investigator Eric Sheldon, the study is also taking place at Miami Research Associates in South Miami, in the US state of Florida.

The H5N1 Indonesia strain belongs to the family of highly pathogenic avian influenza viruses.