FDA Approves Flu Vaccines For 2008-2009 Season

This year's influenza vaccines will include new strains of the virus likely to cause flu in the U.S. during the 2008-2009 season, and the FDA has announced approval of six vaccines containing three strains of the influenza virus. Those vaccines approved, along with the companies that manufacture them, are as follows:

• Afluria from CSL Limited
• Fluarix from GlaxoSmithKline Biologicals
• FluLaval from ID Biomedical Corporation of Quebec
• FluMist from MedImmune Vaccines Inc.
• Fluvirin from Novartis Vaccines and Diagnostics Limited
• Fluzone from Sanofi Pasteur Inc.

Vaccines are modified each season to mirror the virus strains that have the greatest likelihood of spreading. The level of protection offered by the vaccines is dependent upon the accuracy of the match between the traveling strains and those strains contained in the vaccines.

Although the preciseness of the match between the expected virus strains and those strains that actually cause the most illness may not be exact, the vaccines can still provide some measure of protection. Having the vaccine may assist in reducing the severity of virus and help prevent flu-related complications.

Vaccines for the 2007-2008 flu season seemed largely ineffective because unexpected strains began circulating. However, the CDC reported that a record 140 million doses were provided. According to Jesse L. Goodman, M.D., M.P.H., director of FDA's Center for Biologics Evaluation and Research, one of the biggest challenges in the fight against influenza is producing new vaccines every year. He stated, "There is no other instance where new vaccines must be made every year. The approval of flu vaccines is a part of FDA's mission to promote the health of Americans throughout the year."

The FDA changed all three strains for the upcoming season's flu vaccines, which is very unusual. There are usually only one or two strains updated in a given year. The influenza vaccine composition to be used has been recommended by the World Health Organization (WHO) on February 14, 2008, for the Northern Hemisphere's 2008-2009 influenza season. A list of the strains that will be used in the vaccines as well as a list of flu vaccine lots that have been released so far by FDA and are available for distribution by the manufacturers can be viewed at http://www.fda.gov/cber/flu/flu2008.htm.

The FDA, WHO, and the U.S. Centers for Disease Control and Prevention (CDC), along with other institutions, perform a study of virus samples and patterns that have been collected from around the globe throughout the year to identify strains that are likely culprits for causing the flu in the upcoming season. The FDA then selects three strains to include in the vaccines based on recommendations of the FDA Advisory Committee and the forecasts derived from the study data. The selection is made in February of each year to allow manufacturers plenty of production time for the new vaccines.

Influenza is a highly contagious respiratory illness that is caused by influenza viruses. The CDC estimates that an average of 5 to 20 percent of the U.S. population contracts the flu each year with over 200,000 patients being hospitalized due to complications and almost 36,000 cases resulting in death. Those individuals at higher risk for flu related complications include the elderly, young children, and people with chronic medical conditions. Since vaccination remains the key basis for preventing the virus, the distribution of the vaccines to these high-risk groups is critical.

Healthcare personnel are also put at high risk by the nature of their professions and should therefore receive vaccines, but according to Joxel Garcia, M.D., M.B.A., Assistant Secretary of Health for the Department of Health and Human Services, only 40 percent of health care workers in the United States are currently vaccinated against influenza. "Increasing the number of vaccinated health care personnel can be a strong front in the annual battle against the flu," said Garcia. "Health care workers can set an example for the patients they serve as well as decrease the likelihood of contracting and transmitting the virus."

Outbreaks of the flu virus begin as early as October and can last as late as the end of May, according to the Centers for Disease Control and Prevention. Consequently, people should plan ahead for the upcoming flu season.