The Flu Shot Can’t Infect You and Other Flu Facts

Flu facts to know

Flu fact #1: Flu season starts just before Halloween and ends as spring arrives

The flu season runs from October to May. The CDC recommends getting a new dose of flu vaccine each year.

The reason is that there are countless, ever-changing strains of the flu.

Flu fact #2: Vaccines can fight multiple flu strains

Every year a new vaccine has to be developed in order to protect against the three or four different viruses that will emerge in a given year.

Criticism was directed in 2017 at the vaccine, which was said to not be strong enough to combat H3N2, the dominant viral strain of influenza that year, and one that causes more severe disease than others.

Dr. James Cherry, a professor of pediatrics and infectious diseases at UCLA’s David Geffen School of Medicine and Mattel Children’s Hospital, stresses that vaccination naysayers miss the point when critiquing the flu vaccine.

The vaccine can help lessen the symptoms of the flu if you do get sick.

“Even in flu vaccine failures, the illness is less severe, you will still provide yourself with some partial protection,” he said in an earlier interview.

Flu fact #3: A vaccine that’s 40 percent effective can protect a lot of people

No vaccine is perfect. On average, the flu vaccine helps reduce the chance of infection by 40 to 60 percent.

Many people who say they never get sick don’t realize they can contract the flu and shed flu virus without developing symptoms. These people may be passing on the virus to others who are immunocompromised, like young children, pregnant women, or people with cancer.

By getting the shot, you can decrease your chances for contracting the flu and shedding the virus to those at increased risk.

Flu fact #4: Some age groups need different dosages of the vaccine

Dr. Alan Taege, an infectious disease specialist at Cleveland Clinic, told Healthline in a previous interview that children who are 6 months through 8 years old might need two doses of flu vaccine each season. Beyond that, everyone else would just need the regular single dose.

Taege did add that older adults — about 65 years old or older — and people with compromised immune systems might need a higher dosage vaccine. As always, he says you should consult your physician if you have questions about what dosage is appropriate for you.

You should also be aware that the vaccine isn’t immediately effective. It takes around 2 weeks for your body to develop the antibody protection needed to fight off the virus.

Debunking flu myths

Taege says that every year he hears some common misconceptions around the vaccine.

But these myths can be harmful if they lead people to unnecessarily avoid the vaccine.

Myth #1: You can get the flu from the flu shot

“The flu vaccine does not contain a live virus, so you can’t get the flu from the shot. That’s a common misconception,” Taege said.

However, people may feel feverish or achy in the days after getting the shot.

“That doesn’t mean you now have the flu. It means a person’s body is reacting to the vaccine,” Taege said. “Your body says, ‘Oh, there is something here,’ and it then is going to build an antibody ‘fort.’ Typically, a reaction to the shot is mild, and most people can get through with nothing more than Tylenol, or something like that.”

The nasal flu spray, however, is a live virus vaccine, but it’s weakened so you can’t get infected.

Myth #2: You don’t need to get a new flu shot every year

“The different types of the flu mutate every year, so you need to get the new vaccine each year to take account of these variations,” Taege added.

Myth #3: You can be so healthy that you don’t need the vaccine

Taege says it’s a myth that people who are normally healthy don’t need to bother getting a vaccine.

“You can believe you are too healthy to get the flu all you want, but then that changes once you end up getting the flu by not getting vaccinated,” he said. “Even young people can get severe influenza.”

Taege says it’s true that a younger healthier person doesn’t have as high a risk as seniors or young children, but that even a person in their prime health can get sick.

“The more people who get the vaccine, the more chance that we can avoid an epidemic,” Taege said. “It’s called ‘herd immunity’: The more vaccinated means less chance for widespread influenza.”

The socially responsible thing to do

Going along with this point, Cherry says it’s the socially responsible thing to get yourself vaccinated.

2018 was the “100th anniversary of the 1918 flu, the greatest killer of all time. It’s really sobering to see that there were 80,000 deaths,” Cherry said. “Many of those deaths are due to secondary bacterial infections that can come once you get the flu.”

Taege adds that, in addition to getting the vaccine, people should be mindful of “cough etiquette”: Cover your mouth when you cough and avoid putting your hands to your face, since your nose and your mouth are typically how people can pick up the flu. He adds that frequently washing your hands is crucial as well.

“Some people say, ‘Oh, the flu is just a bad cold,'” Taege said. “Well, you can call it a bad cold all you want, but it is more than that. Most people don’t have any risk of dying from a cold unless you are immune compromised.”

Taege points out the flu can be much more dangerous than a simple cold.

“Influenza can kill anyone young or old or in between,” he said. “The flu comes on much more rapidly and much more forcefully than the common cold. Yes, some people, and some who are particularly vulnerable, do die from the flu.”

The bottom line

Experts say now is the time to get your flu shot. Despite common misperceptions, the flu shot can’t give you the flu. You can’t be too healthy that you don’t need it, and you need to get a new shot every year.