Sounds like she might be coming down with a URI. Try heating her food up a little. That'll get her taste buds going and make her hungry.

I don't over vaccinate my cats. Face it. How many times in a person's life do THEY get vaccinated? Once. Why is it cats have to be done every 3 years. You'd think they'd build up immunities to some of these diseases. It could just be a reaction to the vaccinations. Keep an eye on her. Make sure she gets lots of water and does become dehydrated. You can even try adding water to canned food in order to supplement their water intake.

Claudia will be in my thoughts and prayers.