Dr. Siegel: Flu season is here -- here's what you need to know

Influenza is one of medicine’s great enablers. You may start with the flu and end up with something more severe or even life-threatening.

Those with chronic medical conditions such as heart disease, cancer, diabetes and emphysema are at greater risk of complications from the flu. This means they can get sick from the flu but then need hospitalization for something like pneumonia or a heart attack. Pregnant women and their fetuses are also at high risk of flu complications.

Last year was one of the worst flu seasons on record. The Centers for Disease Control and Prevention (CDC) estimated that more than 80,000 people died and more than 900,000 were hospitalized in the U.S. from the flu.

The main problem last year was that the predominant strain was an Influenza A H3N2 (H and N are proteins on the surface of the flu molecule which attach and detach flu from your cells). This strain caused a lot of complications and was fairly resistant to the flu vaccine, which was a big part of the problem.

This year looks better so far. We can predict what will happen here based on Australia’s flu season, which recently ended.

It was a mild to moderate flu year “Down Under” and the predominant strain was an A H1N1, which tends to be much more susceptible to the vaccine. In fact, in Australia this year, vaccinated individuals were 68 percent less likely to see a primary care doctor and 66 percent less likely to be hospitalized due to the flu compared to unvaccinated people. The prevalent strains were also 100 percent sensitive to commonly used anti-flu drugs including Tamiflu.

According to the latest CDC report, flu activity in the U.S. is currently low, so this is not going to be an early-peaking flu season the way it was last year. There is still plenty of time to get the flu shot, and I urge everyone to do so.

Vaccines are not meant just to protect you – they are intended to protect those around you. The more people get the flu vaccine, the less circulating flu virus there is, the less chance an elderly person or a chronically-ill one or a pregnant woman comes down with the flu.

Dangerous myths populate attitudes about the flu vaccine, beginning with the one that you can get the flu from the flu vaccine, which is just a protein (antigen) from a dead virus. In fact, the sniffles or transient aches you may develop after your flu shot is just a mild allergic reaction or your immune system at work.

As a result of these and other flu myths (the vaccine doesn’t work, the flu doesn’t kill, you won’t get it now if you haven’t gotten it before), the flu vaccination compliance rate was once again less than 45 percent for adults last year.

But vaccines are not meant just to protect you – they are intended to protect those around you. The more people get the flu vaccine, the less circulating flu virus there is, the less chance an elderly person or a chronically-ill one or a pregnant woman comes down with the flu. (And pregnant women who get the flu shot are much less likely to need hospitalization.)

Tragically, according to the CDC, 80 percent of the 185 children who died from the flu in the U.S. last year were unvaccinated.

Flu shots, like all vaccinations, are based on the concept of herd immunity. If you are strong and young and healthy but want to help protect those around you who may be more at risk of flu complications, get your flu shot.

And if you come down with the flu, ask your doctor if you or those around you would be better off if you took a drug like Tamiflu, which decreases severity of symptoms, complications, and length of time that you shed the virus.

Though I am predicting a mild flu season with a predominant strain that is less ferocious than last year’s and is well covered by the vaccine, I would like to add a word of caution: Predictions are not facts, and the flu is more easily transmitted during times of low humidity. So be on the lookout during cold weather.

There’s one final flu myth to dispel. My patients frequently mistake common upper respiratory symptoms for the flu. The flu is characterized by fever, body and muscle aches, and fatigue. You may have nasal congestion or a sore throat too, but the way you generally know you have the flu is if you are walking along one minute and need to lie down the next.

Dr. Edward Anderson wrote about influenza (also known as “the grip”) in the Journal of the American Medical Association way back in 1894. What he stated then still holds true today. “This disease has been commented on by some of our ablest men, but it has not received the consideration it deserves, for it extends throughout the habitable world and has destroyed more lives than the cholera and yellow fever put together, attacking alike the centenarian and the child within its mother’s womb.”

Anderson was particularly prescient when you consider he wrote this before the worst flu pandemic on record – the 1918 Spanish flu, which killed over 50 million people worldwide with 675,000 of those flu-related deaths occurring in the U.S., according to the CDC.

But we need to remember that even the mildest flu season sickens millions and kills over 10,000 people. The time to start preparing for the flu is now.