Washington, D.C. ? Flu season is in full swing, with wide outbreaks in 11 states – and a new strain is starting to emerge that this year’s vaccine doesn’t specifically target, the government’s public health chief said Friday.

People still should get their flu shot, and there’s plenty available, Dr. Julie Gerberding, head of the Centers for Disease Control and Prevention, told The Associated Press.

So far, the majority of flu cases are being caused by strains that are a good match to the vaccine – and it should provide some cross-protection against the new bug, too, Gerberding stressed.

Every year, the flu infects up to 20 percent of the population, causes the hospitalization of 200,000 people and kills 36,000.

Flu is a virus, but it can make its victims vulnerable to bacterial infections, in the lungs or the bloodstream, at the same time.

Children are at particular risk, and the CDC this week sent an alert to doctors to watch for young flu victims who might also have such bacterial infections as the notorious drug-resistant staph known as MRSA.

CDC has found flu affecting most of the country but widespread outbreaks in Alaska, Colorado, Hawaii, Kansas, Massachusetts, Mississippi, New Mexico, New York, Pennsylvania, Texas and Virginia.