It’s not too late to get vaccinated against influenza, which has caused 82 deaths so far this season in Canada, doctors say.

Health officials in Canada, the U.S., the U.K., Europe, China and elsewhere are seeing higher numbers of confirmed cases of influenza this year, about halfway through the flu season.

“Some years are little more rough than others. This year seems to be a bit more of a rough season,” infectious diseases specialist at Toronto General Hospital Dr. Isaac Bogoch told CTV’s Your Morning. “Wash your hands, get the flu shot, stay home from work if you’re sick, it really is that simple.”

Bogoch says it’s not too late to get the flu shot. It takes about two weeks to become effective and the flu season typically runs to early March. The flu shot is not perfect, but Canadians should get it because it reduces risk and is the best protection available, the doctor said on Friday. Research also suggests that, even if the vaccine doesn't prevent someone from getting the flu, it could help lessen the symptoms.

As of Jan. 13, there have been 20,349 lab-confirmed flu cases, 2,168 hospitalizations and 82 deaths so far this season, according to the Public Health Agency of Canada.

“The number of hospitalizations is considerably elevated relative to the same period in the previous two seasons,” PHAC said in its weekly FluWatch report, published Friday.

The report says influenza is “widespread” in most of Ontario and southern British Columbia, and present at least sporadically in most parts of the country.

Officials in Australia said its flu season, which is now over, was the worst in more than a decade, and the U.K. is reporting the most severe toll in seven years. The U.S. Centers for Disease Control and Prevention called it a flu epidemic last week and says for the first time in 13 years of monitoring, every state in the continental U.S. is in the midst of “widespread” flu activity.

This year’s virus is proving to be particularly aggressive. Doctors correctly predicted this year’s dominant flu strain, H3N2, but the virus mutated before the vaccine could be manufactured. Some doctors have said the vaccine is only about 10 per cent effective against H3N2. But it is considered to be working well against other strains in circulation.

This year’s B strain, known as B/Yamagata, began circulating in the fall, much earlier than usual.

Doctors in Calgary and Hamilton have reported sharply elevated flu cases that were overwhelming emergency departments and B.C.’s provincial health officer warned in December that flu cases affecting children were rising earlier and faster than expected.

Dr. Amesh Adalja, an infectious disease physician in Pittsburgh, says the H3N2 virus is “notorious for causing severe flu seasons.”

Flu is one of the most contagious infectious diseases. Carriers can spread it a day before they feel symptoms, making it very hard to control, Adalja said during a Friday appearance on CTV News Channel.

The virus can live on surfaces for more than 24 hours and it’s also highly adept at mutating as it jumps from person to person. It takes about 24 hours after a fever has passed for a person to become non-contagious.

Thousands of people die each year of influenza. While they tend to be the very old or young or the medically compromised, every year some young, active, healthy people die, too, says Adalja. In the U.S., victims this season have included an aspiring personal trainer, a marathoner and a 10-year-old hockey player.

“It tends to not be the norm and it tends to be pretty rare but it does happen and it’s important that a young person who is suffering from flu doesn’t procrastinate and gets medical help if they need it.”

Go to the doctor if you have an unremitting fever, are short of breath, can’t stay hydrated can’t get or if you are pregnant or have a condition that suppresses your immune system. The flu usually lasts about a week.

There is hope for a universal flu vaccine in the medium to long term, said Bogoch.

“Nothing is going to come out next year but there is certainly a lot of research and development on how to develop a better flu vaccine, meaning can we develop one shot that would cover for every type of flu. Because we know every year the different strains come and go and the strains can change.”

This year, is the 100th anniversary of the beginning of the 1918 influenza pandemic, which killed at least 50 million people worldwide. It’s been nine years since the last pandemic flu, the 2009 swine flu, which swept swiftly around the world. An international group of scientists concluded in 2013 that it killed 203,000 people.