When Does Flu Season Start?

October 15, 2018

Fall’s great, isn’t it? Pumpkin spice lattes, chunky scarves, cozying up in front of the fireplace. Oh, and flu. Find out when it hits and what you can do to protect yourself.

Although you can get flu at any time of the year, you may be most susceptible during fall and winter. But the more you know, the better equipped you are to deal with everyone’s least favorite cold-weather guest. Read on for the ultimate lowdown on flu season all around the world.

When is flu season in the U.S.?

According to the Centers for Disease Control and Prevention (CDC), flu season in the United States takes place in the fall and winter months. Peak activity seems to mostly fall between December and February, but we do see some activity as late as April and May. So, when are you most at risk of contracting the virus? Well, according to the CDC, February is the cruelest month.
The CDC figures for annual flu seasons from 1982–83 through 2017–18 show that February has the highest amount of flu activity by a significant margin. In fact, over the 36 years that the CDC has been recording flu activity, February has seen the most activity for 15 seasons, more than double the next highest month—December, with 7. So, if you want to remain nice and snot-free for Valentine’s Day, it’s probably worth getting a flu shot!

When is flu season outside the U.S.?

If you’re traveling to other countries, it’s important to remember that flu season differs all around the world. Generally, flu season takes place during the annual cold period of each hemisphere. In the northern hemisphere, for example, flu season tends to last from October to May, just like in the U.S. However, in the warmer southern hemisphere, we’re dealing with an entirely different timeframe. There, flu activity occurs from April to September, while the tropics sees influenza activity occur intermittently throughout the year.

When should I get my flu shot?

Even though October and November are technically the beginning of flu season, there’s relatively little activity in these months, which makes them the perfect time for a flu shot. Of course, the earlier the better, so consider getting ahead of the pack with a September shot, especially if you live in one of the colder states, as that’s the best way to ensure that you’re protected throughout flu season. Plus, there’s the added benefit that you won’t be affected by any shortages of the vaccine. That’s a real problem when flu season reaches epidemic levels, as it did in 2013.
There is, however, one important factor to consider when it comes to the timing of your vaccine, and that’s the time it takes for your body to build up immunity. The CDC says that it takes roughly 2 weeks for your body to develop the robust antibodies that help to defend it against flu and influenza. So, if you’re late to get your flu vaccine, you’ll still be exposed to the virus for a couple of weeks, which may indicate that the sooner you’re able to pick up a vaccine, the better.

How effective is the flu vaccine?

The first thing to remember is that a flu vaccination isn’t a silver bullet. It’s tweaked every year to combat new strains of the virus, but depending on how close the match is, its effectiveness can vary dramatically. In 2017-18, for example, the flu vaccination was relatively poor, and as a result, we saw record-breaking rates of hospitalizations and higher than average fatalities.
In general, vaccinations can reduce your risk of falling ill by 40 to 60%. That’s great, but it’s not foolproof. There are a few other things you can do to boost your body’s immune system and natural defenses, including exercise, getting plenty of sleep, and eating healthy food like fruit and vegetables.
And it’s not just about you. Getting a flu shot can help protect people around you. As the CDC says in their key facts about flu season, “getting vaccinated yourself may also protect people around you, including those who are more vulnerable to serious flu illness, like babies and young children, older people, and people with certain chronic health conditions.”
The good news in the U.S. is that federal law requires flu shots be covered by insurance with no copay or coinsurance charge. And if you don’t have insurance?  Lifehacker has tips on low-cost flu shot options.

We hope you now have a pretty good sense of how to navigate flu season. For a few more ways to beat the big sick, take a look at our Cold and Flu Season Survival Guide.


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