Influenza activity picked up again last week, reaching a new peak this season. Still, this season remains far milder than last year, according to the Centers for Diseases Control and Prevention (CDC).
The flu is now widespread in 48 states and Puerto Rico. Since October 1, 2018, there’s been up to 20.4 million reported cases of the flu, between 8.2 and 9.6 million flu-related medical visits, 214,000 to 256,000 hospitalizations, and 13,600 22,300 deaths, the CDC estimates.
An additional seven pediatric deaths were reported last week, bringing the total of flu-related deaths in children to 41.
Flu season is definitely here, and the CDC expects activity to remain elevated for several weeks.
Some experts attribute the calmer flu season to the effectiveness of this year’s vaccine. But the success of the shot depends on how old you are.
Early estimates found that influenza vaccines have “reduced the risk of medically attended influenza-related illness by almost half (47 percent) in vaccinated people so far this season,” the CDC said.
For children up to 17 years, the vaccine is estimated to be 61 percent effective. Approximately 24 percent of adults ages 50 and older have been protected by the shot.
To compare, the vaccine was reported to be 36 percent effective at this time last year.
The vaccine must be reformulated each year to match the most common flu strains. This year’s vaccine was designed to attack four strains: H1N1, H3N2, Influenza A, and Influenza B.
The predominate strain this year has been the H1N1 virus, with the H3N2 strain popping up more in southeastern states. Because this year’s shot contains these strains, those who got vaccinated are well protected.
The vaccine not only prevents the flu, but reduces the duration and severity of symptoms.
The CDC encourages people who haven’t gotten the shot to do so. Even if you already had the flu this year, it’s worth getting vaccinated.
“Flu vaccines protect against more than one strain of the flu, and just because you were infected with one strain of the flu doesn’t mean you won’t get a second infection with another strain that’s circulating,” Dr. Amesh Adalja, an infectious disease specialist at the Johns Hopkins University Center for Health Security, told Healthline. Adalja is also a spokesperson for Theraflu.
Approximately 90 percent of the cases reported this year are the H1N1 type of flu, which tends to be less severe than last year’s dominant strain H3N2.
In general, fever tends to be greater in those who have H3N2 compared to in those with H1N1. Some doctors have reported difficulties diagnosing this year’s main strain. That’s because some people who’ve tested positive for the flu only exhibited a fever and no other symptoms.
“H1N1 causes a milder flu with milder symptoms. Because of this, the flu may seem like a bad cold, so the less severe, the less likely people are to see a doctor or be diagnosed,” said Dr. Adrian Cotton, an internist and chief of medical operations at Loma Linda University Health.
Typical flu symptoms include cough, fever, fatigue, and body aches. Nausea, vomiting, and diarrhea may occur in more severe cases.
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Health experts predict that flu activity will start to wane within the next month or so. But you shouldn’t let your guard down because new cases will likely be reported as late as May.
“Flu season typically peaks in February, so it’s not surprising to see cases continue to increase. I expect cases will begin to taper off in the next few weeks,” Adalja said.
It’s crucial to continue taking preventive measures against the flu. Wash your hands frequently, get vaccinated, and eat foods rich in vitamins and minerals, such as whole foods and vegetables, to boost your immunity, Cotton said.
If you start experiencing symptoms, see a doctor as soon as possible. Antiviral medications that treat the flu work best when administered within two days of falling ill. Otherwise, it’s best to avoid public places and ride it out at home until your symptoms start to clear up.