Patients receiving a flu shot are at risk for experiencing mild side effects including soreness, redness or swelling of the affected area, fever and aches, according to the Center for Disease Control. Rarely, persons may experience a life-threatening allergic reaction to the vaccine.
Children receiving the nasal spray vaccine may experience runny nose, wheezing, headache, vomiting, muscle aches and fever. Adult patients may exhibit runny nose, headache, sore throat and cough from the nasal spray vaccine. Most individuals experience no side effects from either vaccine; those that do present them immediately after the vaccination for short periods, according to the Center for Disease Control.