NASHVILLE, Tenn. -

Flu activity in Tennessee is picking up in this state, particularly among young and middle-age adults.
    
U.S. Centers for Disease Control and Prevention has found the predominant strain this year is H1N1, the same strain responsible for the 2009 pandemic.
    
Nationally, 1,156 flu-associated hospitalizations have been confirmed since Oct. 1, but many hospitalizations can be prevented by vaccination. The CDC estimates that about 1,600 hospitalizations were prevented in Tennessee last year.
    
Several versions of the vaccine are available including one being offered for the first time that guards against four different flu strains. Traditional vaccines guard against three strains.
    
There is also a high-dose version and a preservative-free one.
    
The CDC recommends vaccination for anyone 6 months or older.