The U.S. Food and Drug Administration (FDA) announced Monday that it has approved a vaccine for 2009-2010 seasonal influenza in the United States.

The seasonal influenza vaccine will not protect against the 2009 H1N1 influenza virus that resulted in the declaration of a pandemic by the World Health Organization (WHO) on June 11, 2009, according to the FDA.

"The approval of this year's seasonal influenza vaccine is an example of the FDA's important responsibility to assure timely availability of vaccine to help protect the health of the American public," said Margaret A. Hamburg, commissioner of food and drugs. "A new seasonal influenza vaccine each year is a critical tool in protecting public health."

Each year, experts from the FDA, WHO, U.S. Centers for Disease Control and Prevention (CDC), and other institutions study virus samples and patterns collected from around the world in an effort to identify strains that may cause the most illness in the upcoming season.

Based on those forecasts and on the recommendations of the FDA's Vaccine and Related Products Advisory Committee, the FDA determines the three strains that manufacturers should include in their vaccines for the U.S. population. The closer the match between the circulating strains and the strains in the vaccine, the better the protection against the disease.

According to the CDC, between five percent and 20 percent of the U.S. population develops influenza each year. More than 200,000 are hospitalized from its complications and about 36,000 people die. Older people, young children, and people with chronic medical conditions are at higher risk for influenza-related complications. Vaccination of these groups is critical.

(Xinhua News Agency July 21, 2009)