One year after H1N1 fears, flu season expected to be normal

This year’s flu shot is an “excellent match’’ for the strains of influenza that have circulated from July through September, said Thomas Frieden, director of the US Centers for Disease Control and Prevention. The CDC expanded its vaccine recommendation this year to everyone older than 6 months old.

“If you’re old enough to ask, you should get a shot,’’ Frieden said at a news conference in Washington.

From June through September, the flu cases tested around the world have followed “typical seasonal patterns,’’ with cases divided among three families of influenza strain: H1N1, H3N2, and Influenza B, according to a study published by the CDC. The report examined the global spread of flu from June through September, the Southern Hemisphere’s winter months.

Influenza is a rapidly evolving virus and the severity of the season depends on which strains are circulating and how well a population has been inoculated. Annual deaths associated with seasonal flu ranged from 3,349 to 48,614 during the last 30 years, according to the CDC. About 90 percent of flu-related deaths are in people ages 65 or older.

Vaccines from Paris-based Sanofi-Aventis SA, London-based AstraZeneca Plc, Basel, Switzerland-based Novartis AG, and CSL Ltd. of Australia protect against three strains of flu that scientists predict are most likely to circulate, the CDC said.

Vaccine makers will produce up to 180 million doses for this flu season, Jeff Dimond, a spokesman for the CDC, said in an interview.

The circulating strains will also respond to Roche Holding AG’s Tamiflu and GlaxoSmithKline Plc’s Relenza, the best-selling treatments for people who become sick with the flu, according to the CDC report. Roche is based in Basel and Glaxo is headquartered in London.

Influenza vaccination rates should be better for the current season than in previous years, Georges Benjamin, executive director of the American Public Health Association in Washington, said Wednesday.