Flu season is bad this year across the country and Island health care leaders are taking note, with an extra immunization clinic announced this week.

Between late November and Jan. 21, there were 87 confirmed cases of flu at the Martha’s Vineyard Hospital. Last year there were 29 cases in the same time period, according to hospital spokesman Rachel Vanderhoop. The illness has hit hardest among people who are elderly, she said.

Meanwhile, the six Island boards of health have teamed up to organize a late-season flu immunization clinic. The clinic will be held on Feb. 15 in the hospital community room. People with insurance should bring their insurance information, but those without insurance will still be able to get immunized free of charge, according to Edgartown health agent Matt Poole. For people who have not had a flu shot, he recommends getting the vaccine as soon as possible.

“We’d like to do it quicker, but with getting the word out and publicizing it, this is the best we could do,” Mr. Poole said.

Tamara Hersh, co-owner of Conroy’s pharmacy in West Tisbury and Oak Bluffs, said they still have flu vaccine available, and she said there has been plenty of interest.

“We can always tell when it’s been in the news because we get more people coming in,” she said. “We’re seeing numbers equivalent to high-peak vaccination season, so this is unusual. Usually November is the latest, and now we’re seeing people in the end of January.”

This year’s flu season has strained health systems across the country, with health care providers reporting the highest rates of flu-related visits since the 2009 swine flu pandemic. Usually, flu season peaks in February or March, but this year it arrived much earlier, sweeping across the country during the holidays. By the end of the third week in January, rates of flu-related hospitalization in Massachusetts were higher than they were at the peak of the last two flu seasons, according to a weekly report from the state Department of Public Health. The state moved from the CDC’s “moderate” level of influenza-like-illness activity to “high” as the illness continued to spread.

With the high volume of cases, there have been reports of some issues in the supply chain of antiviral drug Tamiflu elsewhere in the state.

“I don’t want people to panic,” Ms. Hersh said. “Practice handwashing and avoid people who are sick.” She stressed that at the first sign of fever, it’s important to stay home.

Symptoms of the flu include fever, chills, sore throat, fatigue, coughing, sneezing, stuffy or runny nose, body aches, headaches, and sometimes vomiting and diarrhea. The flu typically kills between 12,000 and 56,000 people every year according to the Centers for Disease Control. It is especially dangerous for adults over 65 and children under 5.

Typically, it’s recommended that people get vaccinated in October to be protected before flu season starts. The vaccine takes about two weeks before it becomes effective.

It’s not too late though to get vaccinated to protect yourself and those around you for the coming months. It’s called herd immunity, and it’s particularly important on an Island, according to Dr. Kathleen Koehler, an internist at Vineyard Medical Care in Vineyard Haven.

“Maybe a given individual doesn’t care if they get the flu or not, but you don’t want to be the person who gives it to an elderly person, or a pregnant woman, or a person with cancer,” Dr. Koehler said. She added the season could extend through May.

The vaccine is reported to be only 30 per cent effective this year, but Dr. Koehler said it can significantly lessen symptoms if flu is contracted.

“We have had a couple of people who did still get influenza after getting the vaccine, but the people who had the vaccine and then got the flu had very, very mild symptoms,” she said. “I would have thought they just had the cold as opposed to the very sick patients you see who didn’t get the vaccine.”

Most clinics and pharmacies on the Island are still administering flu shots on a walk-in basis, but due to high demand, calling ahead is recommended.

Michael Savoy, patient care manager at Island Health Care in Edgartown, said they’ve doubled the number of flu vaccines given over last year, reaching over 350. As to actual cases of the flu though, the numbers at that clinic haven’t been unusual.

“It definitely doesn’t seem as bad on the Island as it does everywhere else,” he said. “So far, I think we’ve dodged a big bullet.”

School nurses echo the sentiment.

“We seem to have it under control here, thank goodness,” said Edgartown School nurse Nicole Barlett. “I’m hearing horror stories off-Island.”

Oak Bluffs school nurse Lana Schaefer sent an email in English and Portuguese to parents with advice from the CDC on how to prevent spread of the flu. The email advises that sick children see a doctor immediately and stay home until they’ve gone at least 24 hours without a fever and without taking fever-suppressing medicine. It also warns to cover coughs and sneezes and cautions against touching the eyes and face, as that’s how germs spread.

“One of those niceties that really needs to go is shaking hands,” said Dr. Koehler. “Just smile, laugh, and say — not during flu season.”

People who plan to attend the Feb. 15 immunization clinic are asked to register with Tisbury assistant health agent Catherine Fuller at 508-684-8309 or by email at cfuller@tisburyma.gov.