One year vaccine

Hi my one year old just had her immunisation at 10am today and this evening (since about 5:30pm) she started getting really fussy and it slowly got worse until 6pm where she seemed really weak and was walking very slowly and breathing harder and she really struggled to bend down to pick something up and was out of breath when she stood back up. Her legs and arms were shakey and she was very sleepy. I gave her her evening bottle and then she fell asleep in my arms and I put her to bed. She’s gone to bed an hour and a half earlier than usual and she is very hot I believe she has a fever. Is all of this normal or should I be worried??