In an effort to expand the supply of flu vaccine available in the United States in the future, a clinical trial of an influenza vaccine widely used in Europe, has begun recruiting participants at four sites nationwide. Funding for the study comes from the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, which is collaborating with the vaccine's manufacturer, GlaxoSmithKline Biologicals of Rixensart, Belgium, to conduct the study.

The new trial aims to enrol 1,000 healthy adults by December 23rd to assess the immune response and safety of the vaccine. More than 126 million doses of the test vaccine, Fluarix, have been distributed in more than 70 countries worldwide, demonstrating a similar safety profile as US-licensed injectable flu vaccine, but the Fluarix vaccine has never been tested or licensed for use in the United States, a release from NIH said.

On December 7, however, Department of Health and Human Services secretary Tommy G. Thompson announced approval of a plan to import up to 4 million doses of Fluarix to be distributed as an investigational new drug (IND). Under an IND, volunteers given the Fluarix vaccine must first sign an informed consent form acknowledging that they are aware of the potential risks and benefits associated with the investigational vaccine.

HHS has taken this step to augment the US influenza vaccine supply because earlier this year one of the two manufacturers of US-licensed injectable flu vaccine was unable to deliver its product, the release added.

"Expanding the number of influenza vaccine sources is critical as we ready ourselves for next year's flu season," NIAID Director Anthony S. Fauci said adding, "The NIAID-supported Vaccine and Treatment Evaluation Units (VTEUs) are structured to perform clinical trials efficiently, enabling us to get needed information rapidly."

"Although the vaccine we are testing has a very long safety record in Europe and other parts of the world, the type of study we are conducting must be done before the vaccine can be licensed for use in the United States," notes lead investigator John Treanor of the University of Rochester Medical Centre.

Four out of every five participants in the new trial will receive Fluarix, while the fifth will receive a placebo. Those receiving placebo vaccine will be offered US-licensed flu vaccine at the conclusion of the month-long study.