Epidemic means that it is a higher than usual number of cases. Some 8.5% of all deaths across the country reported for the week ending January 10 were due to pneumonia and influenza.
This is slightly higher than this time last year. It is not, however, unusual for the flu to have weeks in which it reaches epidemic levels and then ebbs downward during a regular flu season.
The CDC does not track adult deaths. It does keep track of the number of children who die after having the flu.
There were an additional 19 children who have died since the numbers for the United States were reported last week.
That brings the total for this flu season up to 45 pediatric deaths. By comparison this time last year, there had been 27 children who died after having the flu.
Last year, though, was considered a milder flu season.
This year does compare to the rate of deaths during the 2012-2013 season.
In that flu season, like with this one, the H3N2 strain of the virus was found in most of the samples taken from people who were sick. That strain of virus is "nastier," said CDC director Dr. Tom Frieden, since it sends more people to the hospital than other strains.
In the 2012-2013 season, there were 51 pediatrics deaths at this point.
The greater majority of the country has seen widespread flu activity. However, the report says, "there are early signs that activity has begun to decrease in parts of the country."
If you do get the flu, contact your doctor as soon as your symptoms begin -- symptoms include fever, chills, a stuffy nose and sore throat. A doctor can give you some help in the form of antivirals.
Antivirals can shorten the length of time you'll be sick if you take them within 24 to 48 hours of when symptoms first begin. So far this year, antivirals are effective in the fight against the virus, unlike the flu shot, which is only 23% effective.
The manufacturers of the antivirals say there is no supply shortage this year, as there have been in years past.
However, studies have shown that many doctors don't prescribe the antivirals, because it doesn't cure the flu -- it only shortens the time you have symptoms by a day or two. Many doctors believe it should be reserved for those most at risk for complications from the virus.
People who are most susceptible to the potentially deadly symptoms of the flu are people who are very young and and the very old, as well as those with chronic medical conditions.
In December, the CDC warned that this season would be a bad one. That was after the agency determined the H3N2 strain was responsible for the majority of illnesses.
Making matters worse, health officials said the flu vaccine has only been 23% effective this year. Still, they stress a flu shot is the best protection available and if you get one, it can lessen the severity of the symptoms if you do get sick.
Determining what strains to include in the seasonal flu vaccine is not easy.
Each year in February, the World Health Organization holds a meeting at which it tries to predict which of three or four strains of the influenza virus they believe will be most prevalent and that's how they make their recommendations on what vaccine to create to fight the flu season in the Northern Hemisphere.
In September, officials do the same for the Southern Hemisphere.
Their recommendations are based on year-round international data collected on circulating strains of the flu around the world. According to the CDC, the effectiveness of the vaccine in a typical flu season can range from 10% to 60%. Some years are better than others.
But researchers at New York's Icahn School of Medicine at Mount Sinai are working on an alternative that could change that practice. It could even change the need for you to get a flu vaccine every year: A universal flu vaccine.
The universal vaccine would be different from our normal annual vaccine. It would target the conserved domains of the influenza virus -- that's the parts of the virus that don't change or mutate from year to year -- and the hope is that this universal vaccine could keep you protected for up to 20 years.
"We need a vaccine with components of the influenza virus that don't change. Forcing the body into making a response in those conserved domains," said Dr. Peter Palese, chair of microbiology at the Icahn School of Medicine. He runs one of the three labs at Mount Sinai working on this universal vaccine.
Palese says he would have liked to see a universal vaccine "yesterday," but the science wasn't there yet.
"It requires insight and technology we didn't have available to us five years ago," says Palese.
Mount Sinai isn't the only research facility working io this universal vaccine. The CDC is working in an interagency partnership coordinated by the Biomedical Advanced Research and Development Authority (BARDA), a partnership that CDC spokesman Jason McDonald tells CNN has "yielded important successes."
"Part of this effort is the eventual development of a universal vaccine that would offer better and broader and longer-lasting protection against seasonal influenza viruses as well as novel influenza viruses," said the CDC spokesman.
Although this research is advanced, it is still years away from being available for use in humans.