Next year's flu shot will be all-new

Due to new types of flu strains that have spread in the past weeks, the Food and Drug Administration (FDA) decided to scrap last year's vaccine and start from scratch.

FDA's actions in recommending three new strains to be included in the 2008-2009 influenza vaccine bolster the World Health Organization's similar statements. The decision puts vaccine manufacturers on a tight deadline to manufacture entirely new components, instead of using some strains from previous years.

The yearly flu vaccine contains three different strains of the virus, nicknamed A and B strains. While the "A" strain was new each year, the "B" strain was a previous year's virus included, since that version of the illness hadn't run its course through the population yet.

But the 2007-2008 flu season's virulence has been caused by multiple new virus strains. Introducing three new "A" strains would make for a better vaccine for today's climate, FDA feels. But it will challenge vaccine makers, who won't have experience with any of the new strains.