The ominous signs for a harsh flu season have been lurking like the virus itself.
First there was this year’s outbreak in Australia – sometimes a predictor of similar trouble in the U.S. – to the presence of the H3N2 strain, which carries an especially powerful punch.
So far, though, the influenza virus has not begun to take the brutal toll it did two years ago, when 79,000 Americans died of causes related to the flu in the worst such spell this decade.
In its weekly update released Friday, the Centers for Disease Control and Prevention reported two flu-related pediatric deaths this season, with influenza activity remaining low, though it has increased of late.
The percentage of medical visits due to influenza-like illness nudged up to 2.1, which is still below the national baseline of 2.4%. In addition, Louisiana and Maryland were the only states that showed widespread cases of flu.
“Overall, this season has not been as scary. Of course, it’s still early,’’ said Ogbonnaya Omenka, assistant professor and public health specialist at Butler University. “So far, different health departments have been able to contain it in ways that have allowed us not to have some type of significant outbreak or problem.’’
Omenka attributes that to the World Health Organization’s springtime decision to include the H3N2 strain as part of the four-component flu vaccine it recommended for the northern hemisphere.
The Arctic blast currently gripping large swaths of the U.S. may put his theory to the test, forcing people inside and exposing them to others infected with the virus. That’s why the wintertime between December and February is considered the height of the season.
“It’s too early to know which influenza viruses will predominate in the United States this season, but regardless of what is circulating, the best protection against influenza is a flu vaccination,’’ CDC spokeswoman Kristen Nordlund said via e-mail. “Most flu vaccines in the U.S. protect against four different viruses.’’
The CDC recommends flu shots for everybody older than 6 months who does not have contraindications to the vaccine, which is made from either inactivated flu viruses or a single gene from a virus. Neither can cause infection.
Here are answers to some questions about the flu and how to improve the chances of fighting it off:
How effective is the flu shot?
It depends on the year, because the virus is constantly mutating. Sometimes the strain combination selected for the vaccine matches the virus expected to be in circulation, other times not so much.
“While influenza is difficult to predict and circumstances can change very quickly, data to date continue to support the appropriateness of the recommended composition of flu vaccines for the upcoming 2019-2020 season,’’ Nordlund said.
The CDC acknowledges that in years when the vaccine is not a good match, recipients of the shots may get little benefit.
A Mayo Clinic review of past studies says the average effectiveness for adults younger than 65 has been 50-60%.
With those odds, should I bother?
They’re still better than what you’d get in Vegas, and there’s mounting evidence that shows people who are vaccinated endure less-severe symptoms than those who aren’t when they get infected.
Even during the rough 2017-18 season, the CDC estimates flu vaccines prevented more than 7 million cases of the illness, 3.7 million visits to the doctor, 109,000 hospitalizations and 8,000 deaths.
What’s the optimal time to get it?
No later than early December, but October and November are the best months. Remember, it takes two weeks for the human antibodies to develop a reaction to the vaccine.
“With this kind of evidence-based approach to infectious diseases, it’s important to (remain flexible),’’ Omenka said of the ideal timing. “The recommendation may change, because we’re dealing with pathogens that are not static. They are reacting to us trying to check them as well.’’
It’s hard to tell for sure how long the protection lasts because everyone’s immune system is different, but at least six months is a fair estimate. March is typically the lowest month for flu activity.
Is it easy to get a flu shot?
Extremely. The vaccine is available at drug stores throughout the country – often free with insurance plans – at medical offices and clinics, supermarkets with pharmacies and even at Costco.
The CDC said more than 155 million doses of the vaccine have been distributed. Here’s a locator: www.vaccinefinder.org.
How many Americans get the vaccine?
Not as many as the CDC would prefer. The agency estimates only 45% of U.S. adults get inoculated, considerably less than children, who come in at 63%.
President Donald Trump, who in September issued an executive order aimed at improving vaccine production, said in a 2015 radio interview that he’s never had a flu shot because, “I don’t like the idea of injecting bad stuff into your body.’’
The CDC says that “bad stuff’’ won’t give you the flu – contrary to some myths – only help you avoid it.