The American Academy of Pediatrics defines a toddler as a child between 1 and 3 years old. The Food and Drug Administration approved two vaccines, Afluria and Fluzone, for the 2009-2010 flu season for administration in this age group. Clinical studies suggest that the side effects of the flu shot in toddlers are different from the side effects experienced by older children and adults.
Injection Site Reaction
In clinical studies for Afluria, injection site reaction was actually less common in toddlers compared to older children. Among children 6 months to 3 years old, injection site pain, redness and swelling were observed in 37 percent, 38 percent, and 21 percent, respectively. Though redness and swelling are easy to spot, caregivers of toddlers who aren't yet speaking must be sensitive to signs the child is experiencing pain. Pain in a toddler may be manifested as fussiness, irritability, crying and favoring the opposite extremity.
Flu-Like Illness
The flu shot is frequently associated with flu-like illness in adults and children of all ages. In clinical studies for Afluria, the most frequent symptoms in children younger than 3 were: runny nose (48 percent), irritability (48 percent), cough (32 percent), loss of appetite (24 percent), fever--defined as oral temperature greater than 101.3 degrees F or underarm temperature greater than 99.4 degrees--(23 percent), vomiting or diarrhea (15 percent), generalized muscle pain (9 percent), sore throat (5 percent), headache (3 percent), muscle pain (3 percent) and ear ache (3 percent.)
In most cases, symptoms begin 6 to12 hours after the shot has been given and persist for one to two days. In terms of severity, 78 percent of symptoms were rated by parents as mild, 19 percent were moderate and 3 percent were severe. Severe fever, defined as oral temperature greater than 104 degrees F or underarm temperature greater than 103.1 degrees F, was observed in less than 1 percent of children. Similar results were reported for Fluzone.
However, caregivers may want to consider this side effect in determining the appropriate time to schedule vaccination for their toddler.
Allergic Reactions
Allergic reactions are an uncommon side effect of the flu shot. According to the makers of Fluzone, allergic reactions reported among people vaccinated with Fluzone include hives, asthma, angioedema (swelling under the skin) and anaphylaxis. Anaphylaxis, in particular, is a life-threatening allergic reaction that should be taken seriously. According to the American College of Allergy, Asthma and Immunology, symptoms of anaphylaxis in adults and children include trouble breathing, hives or swelling, tightness of the throat, hoarse voice, vomiting, abdominal pain, diarrhea, low blood pressure and rapid heartbeat that may progress rapidly to cardiac arrest and death. Anaphylaxis occurs on or after the second exposure to an allergen. Because toddlers get two flu shots on separate occasions, anaphylaxis is theoretically more likely to follow the second injection. Toddlers are often unable to communicate that they are having an allergic reaction, so it's important for caregivers to be alert to signs that something is wrong.
Acute Disseminated Encephalomyelitis
Acute Disseminated Encephalomyelitis (ADE) is a rare but severe side effect of the flu shot and several other vaccines--including rabies, diptheria and polio. According to a 2008 study in the Journal of Clinical Neuroscience, ADE usually occurs in children, including toddlers. ADE typically presents with abrupt onset of fever, muscle weakness, increased or decreased reflexes, vision changes, impaired balance, forgetting previously known words and other symptoms within at least three months of vaccine administration. Fever usually resolves within a few weeks; however, neurological deficits typically continue for months and even years. ADE is extremely rare and is believed to involve an interaction between the flu shot and a person's immune system.
References
- FDA: Influenza Virus Vaccine for the 2009-2010 Season
- American College of Allergy, Asthma, and Immunology: Anaphylaxis
- 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
