Side effects of the inactivated/dead flu vaccine injection are:

• mild soreness
• redness
• death (very rare)^[52]
• swelling where the shot was given
• fever
• aches

These problems usually begin soon after the injection, and last 1–2 days.^[53]

Side effects of the activated/live/LAIV flu nasal spray vaccine: Some children and adolescents 2–17 years of age have reported mild reactions, including:

• runny nose, nasal congestion or cough
• fever
• headache and muscle aches
• wheezing
• abdominal pain or occasional vomiting or diarrhea^[54]

Some adults 18–49 years of age have reported:

• runny nose or nasal congestion
• sore throat
• cough, chills, tiredness/weakness
• headache^[54]