What Causes Lethargy And Temper Tantrums In A Child After A Flu Shot?

Question: Hello,
My 2 year old daughter is showing some symptoms that have me worried. She got a flu shot and Hep a vaccination last Monday. The past few days she has not been eating or sleeping well. She is irritable, when she is normally easy going. She does not want to be touched or held and has been very lethargic. She is not throwing tantrums, but is irritable and unhappy all the time. She has most of her teeth and has never acted like this while teething. She does not have a fever or any cold symptoms. Sometimes when she cries, she seems in pain, but not always. She is not pulling on her ears or showing any signs of ear infection. She has had a UTI before and does not seem to be showing signs of that either. It is the lethargy that concerns me most. She will just lie on the floor where ever she, when she typically is a child who will only sleep in bed. It's not like she is tired, more like fatigue.
She just puked