What are my flu vaccine delivery options?

The flu vaccine comes in two forms:

  • A shot. A 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.

  • A nasal spray. The nasal spray vaccine consists of a low dose of live, but weakened, flu viruses and is approved for use in healthy people 2 to 49 years of age who aren't pregnant. The vaccine doesn't cause the flu, but it does prompt an immune response in your nose and upper airways, as well as throughout your body.

What are the main differences between a flu shot and the nasal spray vaccine?

Both the flu shot and the nasal spray help protect you from influenza. But there are differences to consider before deciding between the two.

Flu shot Nasal spray
Administered through a needle or a jet injector device — you'll need an injection
Administered through a spray — you won't need an injection
Contains killed viruses — you can't pass the flu along to anyone else Contains weakened live viruses that won't give you the flu but that can, in rare cases, be transmitted to others
Approved for use in people 6 months of age and older Approved for nonpregnant, healthy people ages 2 to 49 years
Can be used in people at increased risk of flu-related complications, including pregnant women and those with chronic medical conditions Not given to those with chronic medical conditions or suppressed immune systems, or to children and adolescents receiving aspirin therapy

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 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 nasal vaccine can cause runny nose, nasal congestion, headache and sore throat.
  • The 2-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 older children and younger adults. 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 flu vaccine and circulating strains of flu virus is close, a flu shot is 71 percent effective in reducing flu-related hospitalizations among adults of all ages, and 77 percent effective among adults age 50 and older. The flu shot may reduce a child's risk by 74 percent.

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.

  • 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.
Aug. 19, 2015 See more In-depth