Influenza Vaccine (Flu Shot and Nasal Spray) for Adults
Side Effects and Risks for Adult Flu Vaccines
Like all medications, vaccines can have side effects. But the risk of harm or death from the influenza vaccine is rare.
The flu shot and nasal spray can cause different types of side effects.
Flu shot side effects may include:
- Low fever
- Muscle aches
- Soreness, redness, or swelling where the shot was given
The nasal spray flu vaccine for adults may cause:
- Headache, muscle aches
- Runny nose, nasal congestion
- Sore throat
Rarely, someone may have a severe allergic reaction to an ingredient in the vaccine. Most of the time, such reactions occur within a few minutes to a few hours of receiving the vaccine. The following can be signs of a severe allergic reaction:
- Behavior changes
- Breathing difficulty, including wheezing
- Hoarse voice
- High fever
- Pale skin
- Rapid heart beat
Seek immediate medical care if you notice any of these signs after receiving the influenza vaccine.