Brian S. Koll, MD
Recently retired as Executive Medical Director for Infection Prevention and Control, Mount Sinai Health System
The seasonal flu is a contagious illness caused by influenza viruses that infect the respiratory tract. When people have the flu, some are only mildly affected, yet others may miss work, be hospitalized, or even die due to complications. Influenza vaccine, though not perfect, is the best way to prevent flu. But if you have always avoided vaccination and have never had the flu, you may wonder, “Why do I need a flu shot?” Here are five good reasons, along with answers to some common questions about flu vaccine.
1. Your luck may run out. People who have never had the flu are very fortunate. But flu viruses mutate every year, so even if you did not get last season’s virus, you may still succumb to this season’s.
2. The symptoms feel awful. After you are exposed to an influenza virus, it takes about two days to develop symptoms, which, unlike those of a cold, come on suddenly. Flu symptoms include high fever, cough, and severe muscle aches and pains, which usually last three to five days. After these symptoms resolve, you may still feel extremely weak, and it usually takes another week or two to build up your strength.
The vaccine is not always effective, but if you do get the flu despite being vaccinated, it will still offer some protection, making your disease less severe.
3. Even healthy, young people can die from complications of flu. Complications can be mild, like a painful ear infection, or severe, like bacterial pneumonia or encephalitis. Having severe influenza increases your risk of hospitalization and death. I once took care of a healthy 18-year-old high school senior who had not had a flu shot. Sadly, he came down with influenza, and died of flu-related pneumonia. The risk of complications drastically increases for older people, even those in their 50s and 60s.
4. You can have the flu and not know it. Only half of people infected will actually have symptoms. You can be completely asymptomatic and unaware you are infected, but still have the virus in your body and still be capable of transmitting it to others.
5. Do it for your loved ones. In addition to protecting you, getting a flu shot also protects your family—especially vulnerable children and grandparents—as well as your friends, coworkers, and everyone else with whom you come into contact.
Who should be vaccinated?
Anyone who is 6 months of age or older should be vaccinated, especially those at high risk of complications from flu, such as young children, older people, pregnant women, people with a chronic illness like diabetes or heart disease, and those with weakened immune systems due to disease or medication like chemotherapy. A study published recently in the journal Pediatrics showed that vaccination significantly reduces children’s risk of dying from influenza.
People with emphysema, asthma, cystic fibrosis, or other lung diseases are especially susceptible to flu-related pneumonia. Those with heart disease are at risk of developing congestive heart failure. Pregnant women exposed to flu are at increased risk for miscarriage or having a baby with a low birth weight, often requiring neonatal intensive care for a few days.
Who should not be vaccinated?
The only people who should definitely not have a flu shot are those who have had a severe reaction to it in the past. If you have ever had Guillain-Barré syndrome, you should discuss vaccination with your primary care physician.
When should I be vaccinated?
You need to get a flu shot every flu season, because the vaccine is updated each year. It is best to be vaccinated before the winter holidays, when you come into close contact with people through travel and indoor gatherings.
The Centers for Disease Control and Prevention recommends vaccination by the end of October, but even if you haven’t been vaccinated by wintertime, it is not too late. Flu season can start in September and last through May, so even if you are not vaccinated until December, you will still be protected for the rest of the season.
What if I have an egg allergy?
Unless you have a history of severe reaction (anaphylaxis) to egg, you can get any type of vaccine. Close to a dozen influenza vaccines are now available—many of them no longer egg-based—so if you are concerned about it, you can request an egg-free vaccine.
Can a flu shot actually give you the flu?
No. It is impossible to catch the flu from a flu shot because vaccines are made either from dead influenza virus or are cell-based, meaning they just contain some genetic material, not the whole virus. A flu shot does not offer protection immediately; it takes up to three weeks for your body to make the antibodies that protect you against influenza. So when people say they got the flu right after having the shot, it means they were exposed to the virus before they developed immunity.
Are side effects possible?
After flu shot, you might have a sore arm, feel a little achy, or develop a fever. These side effects are usually mild and will go away within a couple of days.
I’m concerned about preservatives. What are my options?
Despite the lack of scientific evidence that preservatives cause any harm, manufacturers have listened to patients’ concerns, and the majority of vaccines are now preservative-free.
Is there a special flu shot for older people?
Yes. People 65 or older should get a high-dose flu vaccine. As we age, our bodies need more stimulation to make antibodies, so with a stronger dose, you have a better chance of responding to the vaccine. The down side is that you may be more likely to have a sore arm after getting the shot.
Are there any options for people who hate needles?
For kids, unfortunately not. But for adults age 18 to 64 who want to avoid needles, flu vaccine administered by jet injection, which uses high pressure, is available. The nasal spray vaccine, though still available, is not recommended because it does not provide immunity.
OK, I’m convinced. Where can I get a flu shot?
You can be vaccinated at your doctor’s office or one of the many pharmacies, grocery stores, and walk-in clinics that offer flu shots. To find a convenient location, just plug your ZIP code into the “Flu Vaccine Finder” at Flu.gov.
If you haven’t been vaccinated this season, do it now—for yourself and your loved ones.