“The number of jurisdictions experiencing high activity went from 21 states to 26 states and New York City and the number of states reporting widespread activity went from 36 to 46,” wrote the public health agency in a recent post. “Influenza-like illness (ILI) went from 4.9% to 5.8%. ‎These indicators are similar to what was seen at the peak of the 2014-2015 season, which was the most severe season in recent years.” In some states, like California, emergency rooms have already been overwhelmed with people suffering from the flu.

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Common 2018 flu symptoms

Here are the tell-tale signs of having the flu, according to the CDC: fever and/or chills, cough, sore throat, a runny and/or stuffed nose, body aches, headaches, and fatigue (flu symptoms may present in groups of two or three or all at once). Some flu patients also experience diarrhea and vomiting.

Why the 2018 flu outbreak could be especially deadly

There are a number of factors driving the current flu season, which is already being called “moderately severe” by health officials and has yet to peak (February is usually when flu season is worst). For one thing, it’s been a particularly cold winter in many parts of the U.S., which makes for a more resilient and longer-lingering influenza virus.

And then there’s the matter of the current flu vaccine. It’s unclear if the flu shot will match last year’s effectiveness of about 39%; some estimates have pegged this year’s vaccine’s effectiveness at closer to 30%, although the final numbers will remain unknown until the end of flu season, which can last through May. The flu vaccine is typically somewhere between 40% and 60% effective since scientists have to use some guesswork as to the strains that will be floating around before mass producing the vaccine. Hundreds of thousands of people are hospitalized and tens of thousands die from the flu in any given year, and the young, old, and immune-compromised are at the highest risk.

Furthermore, getting vaccinated for certain strains won’t necessarily protect you from other flu types that are going around. And the dominant strain this year, H3N2, is one that public health experts decry as a particularly nasty one. In fact, it’s a strain that’s likely to lead to more severe symptoms and more deaths among the young and the old.

Is it too late to get a flu shot?

Now for the good news: It isn’t too late to get the flu shot! And, despite concerns about this year’s flu vaccine effectiveness, everyone is still recommended to get one.

Flu shots are often available for free through employer health programs or at retail clinics such as Walgreens and CVS. Even without insurance, a shot will cost less than $20 out of pocket. And it’s still a good idea to receive your flu shot even though the ideal time is in the fall; after all, the vaccine is meant to protect others who might not be able to cope with the sickness as well as you.