This flu season is expected to be more intense than the past few seasons.

“This upcoming flu season is not going to be like the past two flu seasons which were virtually non-existent because of all the social distancing and mask wearing,” Dr. Amesh Adalja, a senior scholar at Johns Hopkins Center for Health Security, said.

Australia recently reported its worst flu season in five years. How the flu season goes in the Southern Hemisphere is a strong indicator for the Northern Hemisphere’s flu season.

“It should be a flu season that is reminiscent of those pre-pandemic,” Dr. Adalja said. He recommends his patients to get a flu shot late October to early November.

Experts say the elderly are at the highest risk for severe disease.

“There are a lot of different flu vaccines and it’s important to talk to your doctor to see which might be the best for you,” Dr. Adalja said.

There are three flu vaccines preferentially recommended for people 65 year or older, by the Centers for Disease Control and Prevention Those include the Fluzone High-Dose Quadrivalent vaccine, Flublok Quadrivalent recombinant flu vaccine and Fluad Quadrivalent adjuvanted flu vaccine.

Vaccine effectiveness can vary, but recent studies show flu vaccination reduces the risk of flu illness by between 40 and 60 percent, according to the CDC.

Dr. Adalja said you can get a flu vaccine and a COVID booster shot at the same time.

“You may have a little bit more side effects when you do that but it is something you can do for convenience,” he said.

On average, up to 41 million people catch the flu every year, which can result in up to 52,000 deaths, according to the CDC.

WASHINGTON, D.C. — After a so-called “twindemic” of COVID-19 and the flu failed to materialize last year, this year's flu season is expected to roar back.

“Because of all the masks and all the precautions, we basically did not have a flu season,” infectious disease expert Dr. David Dodson said of the last flu season.

However, this time around, more cases of the flu are likely to arise.

Dr. Anthony Santella, an infectious disease expert and a professor of health administration policy at the University of New Haven in Connecticut, says this year isn't one to mess around with.

“The flu is incredibly difficult to predict,” he said. “I know everyone wants that crystal ball, 'What's going to happen? When is it going to happen, even outside of COVID?' And that's very challenging.”

He said there are signs and circumstances that point to a far more active, upcoming flu season.

“Children are back at school,” Dr. Santella said. “People are back at work. People are socializing, traveling both domestically and abroad. And that means that those bugs, viruses like what we're talking about, lots of bacteria and other things are circulating.”

Right now, the CDC is tracking confirmed flu cases. Their findings show most of the country is experiencing either a minimal or low number of cases, with the exception of Mississippi, which is seeing a moderate level of flu activity.

Yet, Dr. Santella said that could change as the weather begins to get colder and people spend more time indoors, coupled with COVID fatigue.

“We know the data is pretty clear this year that people feel burdened, they feel frustrated and they feel tired by continuing to maintain those protective health behaviors,” he said.

That is why experts say getting a flu shot by the end of October is so important. The flu vaccines are developed based on the flu strains circulating in other parts of the world.

“This year, they've done things a little bit differently, where instead of having some vaccines that protect against two strains and some that protect against four, all four major vaccine candidates protect against all four strains,” Dr. Santella said.

As for those who have yet to get a COVID-19 vaccine, Dr. Santella said it’s safe to get both together.

“You can get them at the same time,” he said. “There's no harm. There's no counteracting of the products.”

Both of which are vaccines created to help people avoid the worst effects of two deadly viruses.

If there ever was a year to get a flu shot, this one may be it.

Typically, the U.S. Centers for Disease Control and Prevention suggests people get a flu shot by the end of October.

But the coming flu season may be a bad one. With COVID-19 still complicating things, the experts say you may want to do it even earlier.

"Years ago, we would say you should wait as long as you can to get a shot, but if you get it in the fall, that really should cover you through the season," said Dr. Claudia Hoyen, director of pediatric infection control at UH Rainbow Babies and Children's Hospital in Cleveland. "If people get the chance to go ahead and get their flu shot, whenever they can do it is probably good."

Based on the number of viruses she's seen hitting people early this year, she thinks it doesn't bode well for the flu season. Hoyen's children's hospital has been busier this summer compared to last, treating children for a bigger mix of viruses.

"Once we all took our masks off, the viruses did what they do best and found lots of people to give runny noses to," Hoyen said.

What the flu season will look like this year

The U.S. isn't seeing a lot of influenza yet, according to the U.S. Centers for Disease Control and Prevention, but that could soon change.

To predict what kind of flu numbers the U.S. should expect, experts often look to the Southern hemisphere, where flu season usually starts in June and peaks in August.

"The story is mixed so far," said Dr. William Schaffner, a professor in the Division of Infectious Diseases at Vanderbilt University Medical Center.

Australia, with its tight pandemic restrictions on travelers coming into the country, has had very low flu activity, Schaffner said.

"But China, which has more interactions with the outer world, has had a moderate flu season," Schaffner said.

"So we think we'll have at least a moderate season this year."

Children the 'distribution franchise' for flu

Typically what kicks off the flu season is the start of the school year. With more kids going back to the classroom than last year, unless kids are wearing masks, and everyone else for that matter, there will likely be more cases, he said.

"Children are the 'distribution franchise' for the influenza virus. They're on top of each other and they are not the most hygienic little lovelies, so they spread the flu virus amongst themselves," Schaffner said.

"When kids get infected, they shed the virus for a longer period of time than adults do, so they're really the people who bring the virus into the family and spread it about to the neighbors and, well, everybody," Schaffner said.

Flu by the numbers

In an average season, the U.S. sees between 9 and 45 million cases of the flu each year, according to the CDC.

Last year was no average season. Flu was practically non-existent in the U.S. with only a few thousand cases for the entire year. One child died. For comparison, in 2019-2020, there were 199 flu-related deaths in children and 144 the season before that.

The "twindemic" with a high number of flu and COVID-19 cases that some experts predicted for 2020 thankfully never happened.

What's different this year

What may have helped are the extra precautions people took to stop the spread of COVID-19.

Masks, good hand hygiene, limited in-person school, restricted travel and less interaction with others can help prevent COVID-19 and the spread of the flu.

As the country has opened back up, protection from a flu shot therefore becomes even more essential for just about everyone.

A person can get a flu shot and a COVID-19 vaccine at the same time, so if they haven't been vaccinated against COVID-19 yet, or they need a booster, there are no real medical reasons to space them apart from a flu shot, Schaffner said

"If it's your opportunity to get both, I would say get both," Schaffner said. Of course, children 11 and younger cannot be vaccinated against COVID-19 yet.

Flu shots are already available at pharmacies like CVS and Walgreen's.

An added motivation to get a flu shot

While Dr. Anthony Fauci told CNN's Anderson Cooper Monday that the United States could get back to a "degree of normality" by spring of 2022 if the majority unvaccinated in this country get the COVID-19 vaccine, the director of the National Institute of Allergy and Infectious Diseases noted that getting through the winter "could be complicated" by the flu.

Getting vaccinated could certainly keep those numbers to a minimum and with COVID-19 in circulation, Hoyen said people have an added incentive to get a flu shot this year.

Kids under 12 still can't get a COVID-19 vaccine, and while the disease can be milder in the little ones, Hoyen said hospitals are seeing more children with COVID-19 and another virus.

"Even if we don't think these things are important for ourselves, we should really do them for a child in our lives so that they can get back to a little more normal," Hoyen said.