One of the worst flu seasons in years will linger this spring, CDC warns - The current flu season is one of the worst the U.S ...

The flu season has reached its peak, according to new data from the Atlanta-based CDC. This comes just weeks after CDC data shows this year’s flu vaccine was less effective than most years.

The most recent CDC Weekly U.S. Influenza Surveillance Report shows that 7.8% of visits to a healthcare provider were for respiratory illness, the worst since the swine flu pandemic in late 2009.