The Food and Drug Administration said Monday it has approved the new flu vaccine for the season beginning this year.
Each year the FDA works with other federal agencies and global health experts to design a vaccine to protect against the three viral strains most likely to cause the flu. This year's flu shot will be a duplicate of last year's because the same flu strains are still circulating.
The vaccine will be manufactured by six companies: GlaxoSmithKline, CSL Limited, ID Biomedical Corp., Medimmune Vaccines, Novartis and Sanofi.
Between 5 percent and 20 percent of Americans get the flu each year, leading to 200,000 hospitalizations, according to Centers for Disease Control and Prevention.
Last year, the CDC began recommending an annual flu vaccination for everyone except babies younger than 6 months and those with unusual allergies and medical conditions. That recommendation helped boost vaccination rates, along with the appearance in 2009 of swine flu, which was more dangerous than other strains to young people.
The CDC plans to buy about 18 million of the 2011-2012 doses, primarily for government vaccine programs for children.