LITTLE ROCK, Ark. (KTHV) -- Flu activity is rising across the United States and expected to last for several more weeks.

So far this flu season 20 children have reportedly died from the virus. The CDC released maps showing the timeline of the flu from October 2016 to now. October 8th there was very little flu activity across the United States, but as of February 4th the virus has become widespread in 43 states and 23 states including Arkansas are experiencing high levels of activity.

Dr. Tom Cummins, Chief medical officer with CHI St. Vincent said in the past two weeks they've seen a flu spike in their hospital and it's not just patients, “the ER has been really busy with flu patients and our own employees are calling in sick with flu like symptoms.”

Dr. Cummins said typically the flu shot works for type B strain, “unfortunately this year the predominate viral form of the flu is the type A strain and the vaccine is simply just not very effective against that strain of the flu.”

The CDC said this year the flu vaccine has only been 48 percent effective.

Dr. Cummins said he hoped for better results this year, “I'd like the vaccine to be more effective this year but that's just not always the way it works.”

The CDC said children four and under are the biggest group being hospitalized for the flu. A CDC timeline graph just released shows the percentage of visits for the flu across the U.S since 2009, this current flu season is well above the national average.

The CDC said Flu viruses are constantly changing so it's not unusual for new flu viruses to appear each year. Dr. Cummins said the best way to stay safe from the flu is to still get the flu shot and wash your hands.