MINEOLA, N.Y. (CBSNewYork/AP) — The flu has further tightened its grip on the U.S. This season is now as bad as the swine flu epidemic nine years ago.

A government report out Friday shows 1 of every 13 visits to the doctor last week was for fever, cough and other symptoms of the flu. That ties the highest level seen in the U.S. during the 2009 swine flu pandemic.

READ MORE: Police: 2 Children Found Safe Following Carjacking In Newark; Search On For Suspects

And it surpasses every winter flu season since 2003, when the government changed the way it measures flu.

MORE: Debunking Some Of The Biggest Myths Surrounding The Flu

This season started early and has been driven by a nasty type of flu that tends to put more people in the hospital and cause more deaths.

But its long-lasting intensity has surprised experts, who are still sorting out why it’s been so bad.

Nassau County is seeing a skyrocketing number of flu diagnoses.

“This year we are seeing an unprecedented number of cases. We’ve not seen this many cases through January in the season in the last decade. Not even remotely close,” Nassau County Health Commissioner Dr. Lawrence Eisenstein said.

Just two years ago, about 300 people were diagnosed with the flu, but this year the number of confirmed cases is almost 4,000 in the county.

MORE: Tips To Help Avoid Getting The Flu

READ MORE: Nets Rally From 17 Down In 3rd Quarter To Beat Mavericks

“It is not too late to take preventive measures. Flu season does not end now. Flu season continues well into the spring,” Eisenstein said.

He is urging everyone to get vaccinated now.

“The flu shot is a life-saving measure,” Eisenstein said.

County Executive Laura Curran said they’re offering free flu vaccines funded by money from the governor’s health emergency declaration.

The vaccine will be available:

Saturday, February 10th
11 a.m. to 2 p.m. at
Nassau County Department of Health
200 County Seat Drive, Mineola
Visitor’s North Entrance

Tuesday, February 13th
5 p.m. to 7:30 p.m.
Nassau County Department of Health WIC Office
160 N. Franklin Street

Thursday, February 15th
7:30 a.m. to 10 a.m.
Yes We Can Community Center
141 Garden Street, Westbury

Eisenstein said the vaccine takes about two weeks to activate in a person’s body.

MORE NEWS: Islanders' Offense Wakes Up, 11-Game Losing Streak Ends With Victory Over Senators

(© Copyright 2018 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)