What are the side effects of influenza vaccine?
The most common type of side effect is soreness at the injection site. Soreness can last up to two days, is mild and rarely will impair daily activities. Fever, malaise, muscle aches and other symptoms can occur in persons with no previous exposure to the influenza virus used to make the vaccines, for example in children. Symptoms occur 6 to 12 hours following the injection and usually last one or two days. Recent studies in persons over age 65 and healthy young adults, using a type of vaccine called “split-virus influenza vaccine,” show no increase in these symptoms.
