Influenza Vaccine Side Effects

Common Side Effects

The Advisory Committee on Immunization Practices (ACIP) recognizes gastrointestinal symptoms as potential side effects of influenza vaccination, with nausea and diarrhea being reported, though they are less common than local reactions 1, 3, 4
Local reactions, such as soreness at the vaccination site, affect 10-64% of patients and typically last less than 2 days, according to the Advisory Committee on Immunization Practices (ACIP) 1, 2
Systemic symptoms, including fever, malaise, myalgia, nausea, vomiting, and diarrhea, can occur, typically beginning 6-12 hours after vaccination and persisting for 1-2 days, as reported by the Advisory Committee on Immunization Practices (ACIP) 1, 3, 4

The Centers for Disease Control and Prevention (CDC) notes that gastrointestinal symptoms like nausea and diarrhea have been reported after influenza vaccination, though they are less common than local reactions 1, 3
Studies have shown that nausea and vomiting were reported more often among adults being treated with oseltamivir than among persons receiving placebo, and these symptoms might be lessened if oseltamivir is taken with food, according to the American Academy of Family Physicians 4

Children may experience higher rates of fever after vaccination compared to adults, with 11.5% of children aged 1-5 years, 4.6% of children aged 6-10 years, and 5.1% of children aged 11-15 years experiencing fever, as reported by the Advisory Committee on Immunization Practices (ACIP) 1, 2, 3

The influenza vaccine contains only noninfectious killed viruses and cannot cause influenza, as stated by the Advisory Committee on Immunization Practices (ACIP) 5
Respiratory disease or other symptoms after vaccination often represent coincidental illness unrelated to influenza vaccination, according to the Advisory Committee on Immunization Practices (ACIP) 1, 5