A to Z
Data &
Forms &
News &
Licensing &
Rules &
Public Health
Seasonal Flu Vaccine
family ready for fall season

The seasonal flu is a respiratory illness that can be transmitted person to person. Everyone over the age of 6 months should get a seasonal flu shot, especially these groups: 

  • Pregnant women
  • People with chronic medical conditions
  • Healthcare workers
There are four types of seasonal flu vaccines:
  • A flu shot given with a needle, usually in the arm;
  • A nasal-spray flu vaccine for healthy people ages 2-49 who aren't pregnant;
  • An intradermal vaccine that has a much smaller needle;
  • A high-dose vaccine for people over age 65.

About two weeks after vaccination, the body develops antibodies that provide protection against influenza infection. 

Effectiveness of the vaccine

Even if you’ve had a flu vaccination, it is still possible, though much less likely, to get a different strain of flu. The ability of flu vaccine to protect you depends on your age and overall health, as well as the similarity or “match” between the virus strains in the vaccine and those in circulation. Testing has shown that both the flu shot and the nasal-spray vaccine are effective at preventing the flu. Studies also show that a flu vaccine will reduce the severity of illness if you are infected by a different strain of flu virus.

Side effects of the vaccine

The seasonal flu shot and nasal spray have different possible side effects. The seasonal flu shot may have minor side effects that last one to two days. These include redness or swelling where the shot was given and low-grade fever, aches and soreness.

The seasonal flu nasal-spray vaccine may cause minor side effects. In children, side effects include a runny nose, wheezing, headache, vomiting, muscle aches and fever; in adults, a runny nose, sore throat and cough.

Who should not be vaccinated?

There are some people who should not be vaccinated without first consulting a physician. These include:

  • People who have allergies to eggs;
  • People who have had a severe reaction to a previous influenza vaccination;
  • People who developed Guillain-Barré syndrome within six weeks of getting a previous influenza vaccine;
  • Children less than six months of age (influenza vaccine is not approved for this age group);
  • People who have a moderate to severe illness with a fever (they should wait until they recover to get vaccinated).
Where can I get vaccinated?

Use the Flu Vaccine Finder to find a location in your zip code.