Rochester, Minnesota - The influenza epidemic continues across much of the U.S. For those who had the flu earlier in the season, it's possible to become infected with another strain. "People can get two different influenza infections in the same season," says Dr. Pritish Tosh, an infectious diseases specialist at Mayo Clinic.

"Often, it’s not going to be from the same strain," says Dr. Tosh. "Please remember, there’s always one influenza A strain that will predominate but also a couple of influenza B strains that are also cocirculating at the same time."

"Somebody very well this season could develop influenza infection from the influenza A, H3N2 strain that is circulating predominantly, but also later on get infected with one of the influenza B strains that seems to be circulating as well," says Dr. Tosh.

"The circulation of multiple different strains of influenza each season largely is going to be an influenza A strain, but also you have some influenza B strains." Dr. Tosh says these are reasons why people should get vaccinated — even if it’s in the middle of the influenza season.