More Severe Flu Strains Starts to Spread Widely

In terms of severity of the season, Brammer said that no flu season is mild. The severity of the season is simply a comparison between seasons. "There are no good flu seasons," she said.

The death toll of influenza among adults – many of them the frail elderly – is high. So far this year, 22,300 adults have died of a flu, Brammer said, and more than 250,000 people have been hospitalized.

That's still much lower than last year's death toll, which topped 80,000. But the flu is still around, so more people will be hospitalized and die, Brammer said.

If more people were vaccinated, the number of deaths and hospitalizations could be drastically reduced, she noted.

Brammer stressed that if you get vaccinated but still get the flu, your illness will be milder than if you did not get the shot. It's also important that anyone who is around babies and older adults gets a flu shot.

"Vaccinating the family provides a ring of protection around the baby or any other family member at high risk for influenza," she explained.

The CDC stressed that everyone over 6 months of age should get the flu shot.

Last year, vaccination was estimated to prevent 7.1 million illnesses, 3.7 million medical visits, 109,000 hospitalizations and 8,000 deaths, the CDC reported.

As of Feb. 16, flu is widespread in 48 states, and 30 states are experiencing high levels of the disease. In addition, hospitalizations are increasing, the CDC researchers found.

According to the CDC, flu activity is high in New York City and 30 states including Alabama, Alaska, Arkansas, Colorado, Georgia, Indiana, Kansas, Kentucky, Louisiana, Maine, Massachusetts, Mississippi, Missouri, Nebraska, New Jersey, New Mexico , New York, North Carolina, Oklahoma, Pennsylvania, Rhode Island, South Carolina, Tennessee, Texas, Utah, Vermont, Virginia, Washington, West Virginia and Wyoming.

If you get the flu, antiviral drugs like Tamiflu and Relenza can make your illness less severe. But if you're sick, the CDC recommends you stay home so you do not infect others.