According to the U.S. Centers for Disease Control and Prevention, flu can be especially serious in children younger than 2. Therefore, parents are urged to have their children vaccinated. Although no vaccine is available for infants younger than 6 months, the U.S. Food and Drug Administration approved two vaccines, Afluria and Fluzone, for administration in infants older than 6 months. The flu shot is commonly associated with side effects that parents and caregivers might wish to consider when scheduling a vaccination for their child.
Injection Site Reaction
Injection site reaction is one of the most common side effects in infants receiving Afluria. Localized pain, redness and/or swelling have been observed after injection in children ages 6 months to 3 years. Symptoms are typically mild to moderate. In infants, the flu shot is usually given on the outer front portion of the thigh. While redness and swelling are easy to see, parents and caregivers of infants need to watch for other signs of pain such as fussiness, irritability, crying and favoring the opposite extremity.
Flu-like Illness
Flu-like illness is a common side effect of the flu shot in infants. In comparison with true flu, symptoms are mild and usually resolve within 1 or 2 days. The most frequent symptoms in children younger than 3 are runny nose, irritability, cough, loss of appetite, fever--defined as an oral temperature greater than 101.3 degrees or underarm temperature greater than 99.4 degrees---vomiting or diarrhea, whole body muscle pain, sore throat, headache, earache and muscle pain. Severe fever---defined as oral temperature greater than 104 degrees or underarm temperature greater than 103.1 degrees---has also been observed in less than 1 percent of children. Similar results have been reported for Fluzone.
Encephalomyelitis
Acute disseminated encephalomyelitis (ADE), a rare disorder characterized by diffuse inflammation of the brain and spinal cord, might be linked to flu vaccine. According to a 2008 article in the "Journal of Clinical Neuroscience," symptoms of ADE onset abruptly and include fever, muscle weakness, abnormal reflexes, vision loss or changes, loss of balance and other symptoms. ADE is particularly difficult to diagnose in infants because many other symptoms of ADE such as sudden loss of ability to read and write and forgetting previously known words do not apply to this age group. Although ADE is not permanent, deficits can persist for months and even years.
References
- CDC: Seasonal and 2009 H1N1 Flu -- A Guide for Parents
- FDA: Influenza Virus Vaccine for the 2009-2010 Season
- "Journal of Clinical Neuroscience;" Post-Vaccination Encephalomyelitis: Literature Review and Illustrative Case; W. Huynh, D.J. Cordato, E. Kehdi, L.T. Masters and C. Dedousis; 2008
