get ready for the flu season

(FDA) - Influenza is a contagious respiratory illness caused by the influenza virus. Flu season in the United States can begin as early as October and can last as late as May, according to the CDC. The season most often peaks in February or later. The past flu season started off with low levels of activity in October and November 2005, with activity picking up considerably in December. The season peaked in early March 2006 and continued at low levels into May.

The Center for Disease Control (CDC) reports that each year, 5 percent to 20 percent of the 300 million people in the United States get the flu. Most people recover in a week or two without complications. But more than 200,000 are hospitalized with flu complications, and about 36,000 Americans die each year from the flu.

“Vaccination is still the best protection against influenza and can prevent many illnesses and deaths,” says Jesse Goodman, M.D., director of the FDA’s Center for Biologics Evaluation and Research. “Ensuring an adequate, safe, and effective supply of influenza vaccine each year is one of the FDA’s highest priorities.”

Selecting the Strains

New flu vaccine is made each year. “Because the virus mutates, each year’s vaccine may be different from the preceding year’s,” says Goodman. The vaccine is a blend of three different influenza virus strains, and the formulation depends on the virus strains that are predicted to be circulating that particular flu season.

It takes at least six months to produce a flu vaccine, so early in the year, the FDA’s Vaccines and Related Biological Products Advisory Committee meets to decide which three strains of the virus should be used. The formulation selected for the 2006-2007 season includes one virus from last year’s vaccine and two new viruses.

The FDA has licensed four manufacturers to make flu vaccine for the 2006-2007 season. The vaccine manufacturers estimate that between 100 million and 120 million doses will be produced. The increased production will help accommodate expanding vaccination recommendations as well as reduce the risk of shortages.

Vaccination Recommendations

According to the CDC, people who should get vaccinated each year include those who are at high risk for complications from the flu, including people ages 50 and older, and those who are in contact with these high-risk individuals. The upcoming season’s high-risk category includes children ages 6 months to 59 months. Their Advisory Committee on Immunization Practices (ACIP) recommends vaccinating children in this age group as well as their household contacts. The recommendation expands last season’s recommendation to vaccinate children from ages 6 months to 23 months. The expanded age range means that an additional 5.3 million children and 11.4 million household contacts or caregivers should be vaccinated.

The ACIP also emphasizes the importance of giving two doses of influenza vaccine, at least one month apart, to children between the ages of 6 months and 9 years who have never received influenza vaccine.

Although anyone can come down with the flu, infection rates are highest in children, according to the CDC. Children can spread the virus for twice as long as adults and usually shed more influenza virus, making them flu carriers and sources of infection for others.

The youngest children are at the highest risk of influenza-related illness and death, says Henry Bernstein, D.O., who serves on the American Academy of Pediatrics’ Committee on Infectious Diseases. “Children under 6 months of age are very likely to be hospitalized if they get influenza. They are too young to be immunized, so it’s important to immunize all family members, daycare workers, and other close contacts.”