GlaxoSmithKline (NYSE: GSK) has  won approval for the first vaccine to prevent bird flu that allows for a higher number of doses to be made available during a pandemic, U.S. regulators said Friday.

The Food and Drug Administration cleared the vaccine for H5N1 influenza for use in people 18 years of age and older at increased risk of exposure to the virus, the agency said yesterday in a statement. Bird flu has caused serious illness and death outside of the U.S. mainly among people who come in close contact with infected and ill poultry, the FDA said.

“This vaccine could be used in the event that the H5N1 avian influenza virus develops the capability to spread efficiently from human to human, resulting in the rapid spread of disease across the globe,” said Karen Midthun, director of the FDA’s Center for Biologics Evaluation and Research. “Vaccines are critical to protecting public health by helping to counter the transmission of influenza disease during a pandemic.”

The FDA has purchased the vaccine from ID Biomedical Corporation of Quebec City, Canada. It is a subsidiary of GSK.

The vaccine from London-based Glaxo isn’t for commercial use, rather will be kept in the U.S. national stockpile, the agency said. About 60 percent of people who become infected die from bird flu. ID Biomedical Corp., a Glaxo subsidiary based in Quebec City, makes the vaccine with an adjuvant of oil-in-water emulsion to enhance the immune response of patients, allowing the vaccine to stretch further, the FDA said.

About the vaccine, the FDA noted:

  • “The vaccine is made using an egg-based manufacturing process, which is also used for ID Biomedical Corporation’s seasonal influenza vaccine, FluLaval. It contains the adjuvant AS03, an oil-in-water emulsion. An adjuvant is a substance incorporated into some vaccines to enhance or direct the immune response of the vaccinated individual. The adjuvant makes it possible to use a small amount of influenza protein per dose of vaccine to elicit the desired immune response in an individual to prevent influenza disease. Reducing the amount of influenza protein per dose helps to increase the total number of doses of a safe and effective vaccine available for the public during a pandemic.
  • “The H5N1 component and the AS03 adjuvant component are supplied in two separate vials, which must be combined prior to use. The vaccine is administered via intramuscular injection in two doses, 21 days apart.”

GSK operates its North American headquarters in RTP.