Learn about Who Needs A Flu Vaccine.




The Flu Vaccine: Questions and Answers


Printable Version

Influenza (the flu) is more than just a bad cold. People can suffer with fever, cough, sore throat and body aches for several days. Influenza causes thousands of deaths and hospitalizations every year. Getting a flu vaccine is the best way to prevent flu. The flu viruses that circulate can change from year to year and can affect people differently based on the virus and the person’s ability to fight infection. Some flu seasons are worse than others and there is no way to predict how severe the flu season will be.

All 2017-2018 influenza vaccines protect against the following three viruses:

  • A/Michigan/45/2015 (H1N1) pdm09-like virus.
  • A/Hong Kong/4801/2014 (H3N2)-like virus.
  • B/Brisbane/60/2008-like virus (B/Victoria lineage)
Quadrivalent influenza vaccines include an additional B virus:
  • B/Phuket/3073/2013-like virus (B/Yamagata lineage).

All flu vaccines supplied by the Vaccines for Children Program in Washington are quadrivalent.

Who should get the flu vaccination?

The Centers for Disease Control and Prevention (CDC) recommends that everyone gets a flu vaccine.

Some exceptions are babies under 6 months old and those who've had a severe allergic reaction to flu vaccine in the past. People who have a severe egg allergy or have had a rare nervous system condition called Guillain-Barre syndrome should talk to their doctor before they get a flu shot.

If I got a flu vaccination last year, do I need one again this year?

Yes. Each year, a new vaccine is made from flu viruses that are expected to circulate during that season.

When should I get vaccinated?

You should get vaccinated as soon as the vaccine is available. There is still a health benefit in getting a flu shot at any time during the flu season. In the Pacific Northwest, flu activity is usually at the highest level in January or February, but it can go longer.

Do children need more than one dose of flu vaccine per year?

In general, children under age 9 need two doses of flu vaccine the first year they start getting the vaccinations. If a child 6 months to 9 years old has not had two flu vaccines total in their lifetime, they should receive two doses this season. The two doses should be separated by at least 4 weeks.

Are there side effects to the vaccine?

Most people do not have any side effects. If they do happen, they are usually mild. The most common side effects are soreness, redness, tenderness or swelling where the shot is given. The flu vaccine cannot give you the flu.

How effective is the flu vaccine?

The effectiveness of the flu vaccine depends on the match between the flu vaccine and the types of flu viruses that circulate that season. When there is a good match, the flu vaccine is usually over 60% effective in healthy adults. Flu vaccine is somewhat less effective in elderly persons and very young children, but vaccination can still prevent the flu and serious complications.

It is important for healthy people to receive the flu shot to protect people close to them who are at higher risk of complications of the flu.

Is the flu vaccination safe?

Yes, the flu vaccination is very safe. CDC and the Food and Drug Administration (FDA) hold vaccines to the highest safety standards. Flu vaccines have been given to hundreds of millions of people and have been made the same way for decades.

  • As with all vaccines, flu vaccine testing and safety monitoring are done in multiple phases.
  • For vaccines to be approved, the manufacturing facilities and processes must meet standards to make sure that the vaccines are pure and effective.
  • After vaccines are approved, each batch is tested before it is released to check purity and strength. Several systems are in place to watch for possible side effects after vaccines are given.

Why isn't the nasal spray vaccine recommended this season?

Flu vaccine effectiveness studies are done every flu season. Over the last few years, nasal spray has been less effective than flu shots.

The CDC’s Advisory Committee on Immunization Practices (ACIP) reviews flu vaccine effectiveness data every year. Because of its lower effectiveness, the ACIP does not recommend nasal spray flu vaccine for the 2018-2019 flu season.

What about egg allergy?

Most flu vaccines are made using eggs. If you can eat scrambled eggs without a reaction, you can get a flu shot. If you get hives after eating eggs, you can get a flu shot in a medical setting. This way you can get immediate treatment for a severe allergic reaction if you have one. You should be observed for at least 30 minutes to make sure you will not have a serious allergic reaction.

ACIP does not specifically recommend either of these vaccines for seniors over regular flu vaccine. People over age 65 should get a flu shot with any of the currently licensed flu vaccines for adults.

Is there a special type of vaccine available for seniors?

Yes. There are two products approved for people age 65 years or older, Fluzone High-Dose and FLUADTM. Both were made to be more effective for seniors.

ACIP does not recommend any particular flu vaccine. People over age 65 should get a flu shot with any of the currently licensed flu vaccines for adults.

Are there other products available?

The intradermal flu vaccine is a shot that is injected into the skin instead of the muscle. The intradermal shot uses a much smaller needle than the regular flu shot. It is recommended for adults 18-64 years of age. It can cause more skin irritation than the regular flu shot, but there is no deep muscle soreness that sometimes occurs with the regular flu shot.

Is there mercury in the flu vaccine?

Vaccines packaged in multidose vials contain thimerosal, a preservative that protects vaccines against contamination. Thimerosal contains a small amount ethyl mercury. Other than minor reactions like redness and swelling at the injection site, there is no evidence of harm caused by the small amount of thimerosal in vaccines.

Vaccines packaged in single-dose vials and pre-filled syringes are thimerosal-free. They are usually given to children under age 3 and pregnant women. Most of the flu vaccines licensed by the FDA for use in the United States do not contain thimerosal.

Does the flu vaccine cause Guillain-Barre syndrome?

In 1976, a type of influenza (swine flu) vaccine was associated with Guillain-Barré Syndrome (GBS). Since then, flu vaccines have not been clearly linked to GBS.

GBS is a rare problem in which a person’s own immune system damages the nerves, causing muscle weakness and sometimes paralysis. Studies of the risk of GBS from seasonal influenza vaccines have concluded that there is either no risk or a risk of about one per million people vaccinated. This is much lower than the risk of complications and death from influenza. Influenza can also cause GBS.

The causes of GBS are not completely understood. About two thirds of cases of GBS are preceded by upper respiratory infections or diarrhea.

For more information about flu and flu vaccines, visit: