Flu Season: What to Know This Year

Influenza virus

Editor's Note: This story was updated May 13, 2019, to include new statistics on the flu season.

The longest flu season in 10 years is winding down, CDC data show.

The CDC reports widespread activity in just two states: Massachusetts and New York. You can see the CDC's map here.

The long season has been partially caused by a second wave of flu dominated by the A strain H3N2, which has been causing more severe illness.

The agency reports 20,000 to 30,000 flu-related deaths in the United States so far this winter, about 300,000 flu-related hospitalizations, and around 25 million flu illnesses.

It also said that 106 children have died this season for flu-related reasons.

The largest group of people needing to go to the hospital for flu has been adults 65 and older, with the second largest group being children 4 and younger.

Since 2010, the flu has affected about 9 million to 35 million annually.

Here is what else to know about flu.

What is the latest news on the flu season?

In its most recent report, the CDC said flu activity was widespread only in Massachusetts and New York. Puerto Rico and seven states -- Arizona, Connecticut, Kentucky, Nevada, Ohio, Utah and Washington -- reported regional activity. The rest had either local or sporadic activity except for Alaska, which had no activity. 

How effective is this year's flu vaccine?

The CDC says it’s impossible to predict how well the vaccine will work. But the agency said in January that the vaccine has been a better match so far this year.

There are many strains of the two types of flu viruses, A and B, that infect humans. In order to have flu shots ready for flu season, experts have to decide, months in advance, which strains to include in the vaccine. Because strains can change quickly, the vaccine is not always a good match.

Even when the vaccine is a good match, the way it is produced may limit how well it works.

Most flu shots are grown in eggs, which may change the viruses and affect how well they work.

Where do I get the flu vaccine?

It's offered at doctors' offices, clinics, health departments, college health centers, pharmacies, and at many offices and some schools.

Many insurance plans pay for the annual vaccination, and older adults covered under Medicare Part B can get the vaccine free, with no copay or deductible.

To find a source for vaccines in your area, go to the Vaccine Locator (http://vaccine.healthmap.org).

How do experts decide what to put into the flu vaccine?

During flu season, experts study samples of the viruses circulating to evaluate how well the vaccine protected against those viruses. They use that information to help make their decision for the next one. This year, the vaccine will protect against two A strains -- H1N1 and H3N2 -- and a B strain. The quadrivalent vaccine will protect against an additional B strain.

Like all other vaccines, the one for flu isn't perfect, but it cuts the risk of illness from 30% to 60% in the general population, the CDC says. In general, vaccines work better against influenza B and influenza A (H1N1) viruses than they do against influenza A (H3N2) viruses, the CDC says.

Who gets hit the hardest?

Last year’s flu season was one of the worst on record, with the highest death toll in decades. U.S. Surgeon General Jerome Adams, MD, said an estimated 80,000 Americans died of flu and its complications and about 900,000 landed in the hospital.

While seniors were hit the hardest last season, it was also hard on children. Thousands of U.S. children had been hospitalized and 180 kids had died of flu-related causes. Among the children who died, about 80% had not had a flu shot, according to the CDC.

Children younger than 2 are especially vulnerable. Those ages 6 months and under are also much more likely to get complications, but they're too young to be vaccinated, so the best idea is to be sure everyone in contact with them is vaccinated.

Adults ages 65 years and above are at greater risk than younger, healthy adults due to weakened immune systems. Typically, these older adults account for most flu-related deaths and more than half of flu-related hospitalizations.

Pregnant women, as well as those who have delivered a baby in the previous 2 weeks, are more likely to have a severe illness than women who aren't pregnant.

Anyone with a chronic medical condition is more likely to have complications. These conditions include:

  • Asthma
  • Diabetes
  • Heart disease
  • Obesity
  • A compromised immune system due to cancer, HIV, or other conditions

When does flu season begin and end?

Although you can get the flu anytime, flu season starts in October and can go as late as March and even April. But ''it usually peaks in the U.S. in February, says William Schaffner, MD, medical director of the National Foundation for Infectious Diseases. 

What types of flu shots are available this year?

For the 2018-2019 season, there are several vaccines:

  • Trivalent vaccines, which protect against three flu strains: two A and one B
  • Quadrivalent vaccines, which protect against fours strains: two A and two B
  • A high-dose vaccine that protects against two A and one B strain, meant for adults 65 and above, who usually have weaker immune systems
  • An adjuvanted vaccine, made using an ingredient that helps trigger a stronger immune response, is also an option for older adults. It protects against two A strains and one B.
  • A recombinant vaccine is an egg-free option for people with egg allergies. It protects against two A strains and one B strain.
  • A nasal spray vaccine for people ages 2 to 49 that protects against four strains: two A and two B. It is not for pregnant women and people with weakened immunity, among other conditions.

Children who have never been vaccinated against influenza will need two doses, spaced at least 4 weeks apart.

Is one type of vaccine better than another?

While the quadrivalent vaccine protects against more viruses, the CDC says there is no preference among the recommended and approved vaccines. Ask your doctor which is best for you. Different vaccines are approved for different age groups.

Up to 166 million doses of the flu vaccine are expected to be produced for this flu season, including 119 quadrivalent. However, if it is not available, it is better to get another flu vaccine than to wait for it, the CDC says.

Any flu shot is better than none. Don’t delay getting one if you can't get your first choice.

Who should get a flu shot, and when?

In general, everyone over 6 months of age should get vaccinated -- the earlier the better for getting the vaccine. Late September is a good time, Schaffner says, and even into October and beyond.

The AAP says that all children 6 months and older should get the shot to help cut the risk of severe illness and death as soon as possible, but preferably by the end of October. 

Who should not get a flu shot?

Anyone who got Guillain-Barre syndrome within 6 weeks of a previous flu vaccination should not get vaccinated, the CDC says. Nor should anyone with a known severe, life-threatening allergy to any ingredients in a vaccine.

What about pregnant women? A recent study linked flu vaccine and odds of miscarriage.

In that study, published in the journal Vaccine in September 2017, researchers found a link -- but could not prove cause and effect -- between women who were vaccinated against influenza A H1N1 strains for two consecutive seasons and miscarriage.

But previous research had not found a higher risk, says Schaffner, who's also a professor of preventive medicine at Vanderbilt University School of Medicine, Nashville. The researchers are continuing to study the issue, and some experts wonder if the finding might be a statistical fluke, he says.

The CDC continues to recommend vaccination for pregnant women.

Pregnant women who get vaccinated also cut the chances of flu in their baby, Schaffner says. "Some of that protection goes across the placenta and protects the baby for the first 6 months" before immunization is recommended, he says.

How long does it take for the flu shot to become effective?

It takes about 10 days to 2 weeks for the vaccine to reach its top strength, says Schaffner.

What about the nasal spray flu vaccine?

The nasal spray vaccine, FluMist, is once again being recommended by the CDC. Although it didn’t work well against H1N1 viruses, it did against some B viruses and H3N2 viruses. It’s available for children 2 and older who don’t have a compromised immune system.

I hate needles. What can I do?

Even some health care providers have needle phobia, says Patricia Stinchfield, a registered nurse who is senior director of infection prevention and control and a pediatric nurse practitioner at Children's Minnesota.

The strategy she suggests to help children through the shot can also work for needle-wary adults, she says. "Close your eyes. Breathe through your mouth. Relax your arm. Imagine your favorite place. Before you know it, it will be over."

What are common symptoms of the flu?

They usually come more suddenly than cold symptoms. They include fever, feeling feverish, the chills, having a cough, sore throat, runny nose, muscle or body aches, headache, and fatigue. Less common are vomiting and diarrhea. Children are more likely to have vomiting and diarrhea than adults are, the CDC says.

Not everyone with the flu has a fever.

What should I do I if I think I am getting the flu?

Stay home, rest, and avoid contact with others except to get medical care if needed, experts say. Avoid contact with others for at least 24 hours after the fever subsides to avoid spreading the flu.

Be on the lookout for emergency warning signs that you may be getting serious flu-related complications, the CDC says.

In children, these include:

  • Fast or troubled breathing
  • Bluish skin color
  • Severe irritability
  • Fever plus a rash
  • Lack of interaction
  • Not drinking fluids
  • Symptoms that improve then return with fever and a worse cough

In adults, they include:

  • Breathing trouble
  • Pain or pressure in the chest or abdomen
  • Dizziness or confusion
  • Severe or persistent vomiting

Symptoms that improve but then return with a fever and worsening cough.

Emergency flu symptoms kids

What are the treatments for the flu?

The FDA in October approved the first new flu treatment in nearly 20 years: baloxavir marboxil (Xofluza). The new treatment joins the other three approved antivirals for flu, including oseltamivir (generic or Tamiflu), peramivir (Rapivab), and zanamivir (Relenza).

Antiviral drugs can lessen your symptoms and shorten sick time by 1 or 2 days, according to the CDC. These are prescription medicines in various forms, such as pills, liquid, an inhaled powder, or an IV solution. Ask your doctor if they are right for you.

They may also have side effects. Tamiflu may cause nausea and vomiting, and it may make headaches and psychiatric effects more likely. And in a recent study, it didn’t lessen complications. 

It's important to start the drugs early, as studies show they work best when started within 2 days of getting sick. But your doctor may decide they can still be helpful if started later than that.

What alternative treatments are people trying?

Elderberry has received a lot of buzz, but health experts say the jury is out. This natural remedy may help treat flu and cold symptoms by cutting congestion and perhaps by making you sweat more, experts at the University of Maryland say. In one study, an elderberry extract called Sambucol helped shorten how long the flu lasts by about 3 days. But the product also has other herbs, plus vitamin C, so it's unclear whether the elderberry alone helped.

In another study, a lozenge with elderberry extract helped ease flu symptoms if taken within a day of when the symptoms started. And in the lab, some researchers found elderberry could kill the H1N1 flu virus -- but that was in test tubes, not people. According to the National Center for Complementary and Integrative Health: "Although some preliminary research indicates that elderberry may relieve flu symptoms, the evidence is not strong enough to support its use for this purpose."

And a caution: The raw berries have a chemical similar to cyanide and must be cooked.

There are reports of people putting slices of red or white onions on the soles of their feet and then putting on socks to try to cure flu, cold, cough, or fever.

While that remedy has been making the rounds, there's no evidence that it works. Backers say the sulphuric compounds from onions on the feet can enter the body and then kill bacteria and viruses. But medical experts roundly dismiss the idea.

Snopes.com, the website devoted to squashing rumors and myths, gives it a ''False" stamp, adding:  ''Sleeping with onion slices in your socks might give you more space in bed, but it's certainly not fixing anything medically."

On the plus side: You won't hurt anything, except maybe your personal relationships, by trying it.

Besides getting vaccinated, what else can help lower the chance of getting the of flu?

Everyday preventive actions are important. Avoid people who are ill, and practice good hygiene such as washing your hands often and covering your cough. If you are sick, stay home.

HealthDay contributed to this article.

WebMD Medical Reference Reviewed by Hansa D. Bhargava, MD on September 13, 2018


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