What are my flu vaccine delivery options?
The flu vaccine is recommended as an injection only. While there is an FDA-approved nasal spray vaccine that consists of a low dose of live but weakened flu virus, the CDC no longer recommends nasal spray flu vaccinations because during recent flu seasons, the spray has been relatively ineffective.
The flu shot contains an inactivated vaccine made of killed virus. Because the viruses in this vaccine are killed (inactivated), the shot won't cause you to get the flu, but it will enable your body to develop the antibodies necessary to ward off influenza viruses.
The injection is usually given in a muscle in the arm. If you're between 18 and 64 years of age, you may also choose an in-the-skin (intradermal) vaccine, or you may prefer to have your vaccine delivered using a jet injector device, which uses a high-pressure, narrow stream of fluid to penetrate the skin instead of a needle.
Can the vaccine give me the flu?
No. The flu vaccine can't give you the flu. But you might develop flu-like symptoms — despite getting a flu shot — for a variety of reasons, including:
- Reaction to the vaccine. Some people experience muscle aches and a fever for a day or two after receiving a flu shot. This may be a side effect of your body's production of protective antibodies.
- The two-week window. It takes about two weeks for the flu shot to take full effect. If you're exposed to the influenza virus shortly before or during that time period, you might catch the flu.
- Mismatched flu viruses. In some years, the influenza viruses used for the vaccine don't match the viruses circulating during the flu season. If this occurs, your flu shot will be less effective, but may still offer some protection.
- Other illnesses. Many other diseases, such as the common cold, also produce flu-like symptoms. So you may think you have the flu when you actually don't.
What kind of protection does the flu vaccine offer?
How well the flu vaccine works can vary. The flu vaccine is generally more effective among healthy children age 2 and older and adults age 64 and younger. Some older people and people with certain medical conditions may develop less immunity after receiving a flu shot.
According to the CDC, in past flu seasons when the match between the flu vaccine and circulating strains of flu virus is close, a flu shot is 40 to 60 percent effective in reducing the risk of getting influenza among people of all ages.
Can I lower my risk of the flu without getting a flu shot?
With or without a flu shot, you can take steps to help protect yourself from the flu and other viruses. Good hygiene remains your primary defense against contagious illnesses.
Sept. 19, 2017
- Wash your hands often and thoroughly with soap and water.
- Use an alcohol-based sanitizer on your hands if soap and water aren't available.
- Avoid touching your eyes, nose or mouth whenever possible.
- Avoid crowds when the flu is most prevalent in your area.
- Practice good health habits. Get plenty of sleep, exercise regularly, drink plenty of fluids, eat a nutritious diet and manage your stress.
See more In-depth
- Frequently asked questions 2017-2018 influenza season. Centers for Disease Control and Prevention. https://www.cdc.gov/flu/about/season/flu-season-2017-2018.htm. Accessed Aug. 29, 2017.
- Hibberd PL. Seasonal influenza vaccination in adults. https://www.uptodate.com/contents/search. Accessed Aug. 25, 2017.
- Key facts about seasonal flu vaccine. Centers for Disease Control and Prevention. https://www.cdc.gov/flu/protect/keyfacts.htm. Accessed Aug. 29, 2017.
- Vaccine effectiveness — How well does the flu vaccine work? Centers for Disease Control and Prevention. https://www.cdc.gov/flu/about/qa/vaccineeffect.htm. Accessed Sept. 14, 2017.
- Centers for Disease Control and Prevention, et al. Prevention and control of influenza with vaccines: Recommendations of the advisory committee on immunization practices, United States, 2017-18 influenza season. MMWR. 2017;66:1. https://www.cdc.gov/mmwr/volumes/66/rr/rr6602a1.htm. Accessed Aug. 24, 2017.