Influenza cases continued to rise last week, but the rate of increase may be plateauing, according to statistics released by the Maine Center for Disease Control and Prevention on Wednesday.

Maine had a total of 2,307 confirmed cases of the flu for the 2017-18 flu season, which runs from October to May. That number reflects 538 new cases for the week ending Jan. 27.

There were 531 new cases the previous week, and the last three weeks have been the most severe in Maine so far.

So far, 527 Mainers have been hospitalized with the flu. Twenty-eight Mainers have died of flu-related causes this season compared to 71 for the 2016-17 season.

The dominant strain of flu this season is influenza A H3N2, which is causing more severe symptoms.

Colleen Hilton, president of Maine’s Visiting Nurse Association, said the organization decided to host a clinic this Friday in South Portland in response to the severity of the flu season. Typically, the VNA runs clinics in the fall, in advance of or at the very beginnings of flu season. The clinic will be 1-4 p.m. Friday at VNA Home Health Hospice, 50 Foden Road, South Portland.

“We’re very concerned about the elderly and people with chronic conditions at home getting the flu. We have about 400 doses left of the vaccine so we thought we would use them,” Hilton said. “It’s not too late to get a vaccine and try to limit your exposure to the flu.”

It’s not known yet how effective the flu vaccine will be this year, but the vaccine is never 100 percent effective because the flu virus is always mutating. In order to get the vaccine on the market in time, scientists must predict months in advance the predominant strains of flu that will be circulating. The vaccine was 48 percent effective in 2016-17 and 59 percent effective in 2015-16, according to the CDC.

For those who contract the flu despite getting immunized, studies show that symptoms are usually much more mild for those who received their flu shots.

The city of Portland will also be hosting a flu clinic, from 11 a.m. to 2 p.m. on Monday, at City Hall in downtown Portland.

Maine had 5,830 confirmed flu cases in 2016-17, although the predominant strain was less virulent, and there were fewer hospitalizations.

Flu activity in Maine is widespread, and the nation is suffering through one of the most severe flu seasons in years, according to the federal CDC, with more than 83,000 confirmed cases across the nation.

The actual number of flu cases is much higher than gleaned from official reports because many people recover at home and are never tested.

Symptoms include fever, chills, muscle aches, swollen lymph nodes, sore throat, headaches, fatigue and coughing.

Hilton said that anecdotally, she’s hearing that this year’s flu season is among the most severe in recent years.

“This year’s flu virus is a pretty resistant strain. People are getting really sick,” Hilton said.

Dr. Dan Jernigan, director of the influenza division at the U.S. CDC, told reporters last week that it’s a “tough flu season” affecting all areas of the country.

“For the past three weeks, the entire country has been experiencing lots of flu, all at the same time,” said Jernigan, according to a transcript posted on the CDC website. “While flu activity is beginning to go down in parts of the country, it remains high for most of the U.S., with some areas still rising.”

Joe Lawlor can be reached at jlawlor@pressherald.com or 791-6376

Twitter: @joelawlorph