HUNTSVILLE — It’s not yet an epidemic, but it’s close.

With widespread cases of influenza being reported in most U.S. states, the virus is just below the threshold of activity that the Centers for Disease Control & Prevention use to declare an epidemic. If and when that happens, it will mark the first flu epidemic in America since the 2014-2015 flu season.

Like that deadly 2014-2015 flu season, which caused about 20,000 deaths in the U.S., this year’s predominate strain of flu is H3N2. It’s a strain of influenza Type A that isn’t necessarily as virulent as some other strains of flu, but it can mutate quickly, placing more of a burden on the body’s ability to fight it off.

According to CDC data, the number of hospitalizations for flu-like illness have doubled over the past two weeks, and are 35 percent higher than they were at the same time last year. Most of those hospitalized have been older than the age of 65, but the flu can be deadly for younger people — even those without underlying health conditions.

The Tennessee Department of Health reported Monday that a Middle Tennessee woman who was pregnant died of flu. And three children in Tennessee have died of flu so far this month.

Children and pregnant women are among the groups of people at highest risk for flu complications. During the 2014-2015 H3N2 flu epidemic, 147 pediatric deaths were recorded in the U.S.

This year’s flu season was expected to be bad, after an unusually difficult flu season in the Southern Hemisphere. In Australia, for example, media reports called it the worst flu outbreak on record. In the U.S., there have been reports of tents set up at overcrowded California hospitals, where the death toll had reached 27 as of Friday — up from just three during the same period last year. In Texas, some hospitals were turning away non-emergency patients due to overwhelmed emergency rooms. And in Arkansas, 14 percent of all physicians clinical visits were due to flu-like symptoms.

Tennessee’s flu outbreak is not quite that bad yet, but the Volunteer State is bracing for it to get worse. As a result, the Scott County Health Department announced Monday that it is offering free vaccinations.

“Getting a flu vaccine is the best way to protect you, family members and others from the flu and help keep our community healthy,” Scott County Health Director Art Miller said. “We urge everyone who has not received a flu shot yet to get one now.”

Experts say it is never too late to receive the vaccine. Dr. William Schaffner, an infectious disease specialist at Vanderbilt University in Nashville, told ABC News that while there is still time to get the vaccine, it can take two weeks for a person’s body to build up defense against the flu virus.

“It is late and so do not walk, run. Run to your provider’s office or pharmacy to get the vaccine,” Schaffner said.

While this year’s vaccine is not believed to be as effective as the World Health Organization would like, with effectiveness being perhaps as low as 10 to 20 percent, the benefits of receiving the vaccine are still many, experts say.

“It’s an imperfect vaccine, but it’s the best we have, and it still does provide a terrific amount of protection,” Schaffner told ABC News.

Experts say that even among vaccinated people who are infected by the flu virus, their illness is likely to be less severe.

The vaccine is especially important for the elderly, children, pregnant women and others with chronic health conditions, according to the CDC, which recommends that every person older than six months of age receive the vaccine. In the 2013-2014 flu season, the CDC reported that 90 percent of children who died did not receive the vaccine.

Scott Countians can inquire about a free vaccine by calling the health department at 423-663-2445.

In the meantime, the health department joined the growing chorus of calls for sick persons to stay home to avoid spreading illness to others.

Among other precautions that can be taken, the health department said, are to wash your hands thoroughly with soap and water or use an alcohol-based hand sanitizer, cover your nose and mouth when coughing or sneezing, and avoid touching your eyes, nose and mouth.