GlaxoSmithKline

(GSK) - Get Report

said the Food and Drug Administration approved its flu vaccine, Fluarix, for sale during the upcoming flu season.

The FDA's action means there will be at least three vaccine suppliers this year -- GlaxoSmithKline,

MedImmune

(MEDI)

and

Sanofi-Aventis

(SNY) - Get Report

.

The FDA also is reviewing efforts by

Chiron

(CHIR) - Get Report

to resume selling its flu vaccine after

manufacturing problems caused the cancellation of all sales during the previous flu season.

GlaxoSmithKline provided about 1.2 million doses of vaccine last year on an emergency basis. A spokesman said Wednesday the company will provide about 8 million doses this year. Fluarix is only approved for people 18 years and older.

"The shortage of flu vaccine last year was a reminder of the importance of vaccines in health care," said Jean-Pierre Garnier, CEO of GlaxoSmithKline, in a prepared statement. His company is in the midst of a

major expansion of its vaccine efforts worldwide, including a doubling of flu vaccine production by 2008.

GlaxoSmithKline's stock was up 48 cents, or 1%, to $48.53 in midafternoon trading.

The federal Centers for Disease Control and Prevention says it cannot predict how much vaccine will be needed for the upcoming flu season. The CDC said recently that Sanofi-Aventis expects to produce 50 million to 60 million doses, and MedImmune is good for 3 million doses of its FluMist nasal spray vaccine.

Sanofi-Aventis plus MedImmune can probably make enough "to supply the historical demand for influenza vaccine among groups considered to be at high risk ... as well as among health-care workers and household contacts of children less than 6 months of age," the CDC says. However, MedImmune's vaccine isn't approved for the very old or the very young, which are both high-risk groups. FluMist is approved for healthy people ages 5 to 49 who aren't pregnant.

The CDC can't say if there will be a shortage of vaccine. If so, the agency says it may establish a priority list of the most vulnerable people. The CDC expects to publish information on vaccine supplies in early September "and, if necessary, will provide recommendations regarding prioritization."

The FDA says its Fluarix decision marked the first time a vaccine had been approved via an accelerated review process for "serious or life-threatening illnesses." That means the drug met a clinical-trial goal "that is reasonably likely to predict ultimate clinical benefit, usually one that can be studied more rapidly than showing protection against disease," the agency says.

GlaxoSmithKline showed the drug "made levels of protective antibodies in the blood that FDA believes are likely to be effective in preventing flu," the agency adds. The company will conduct additional studies "to verify the clinical benefit of the vaccine," the FDA says.

"Previous shortages highlighted the need for additional influenza vaccine manufacturers for the U.S. market," said FDA Commissioner Lester Crawford in a prepared statement. "Accelerated approval has allowed us to evaluate and approve Fluarix in record time so that we can make available additional safe and effective flu vaccines."