You can see the site of the vaccination. Please click on the link below the title to read a discussion on this topic. Thanks. The photographer (the cat’s owner) said on Flickr:
“Dopey developed a nasty reaction to the vaccinations he was given at the injection site. He lost almost 3 pounds from lack of appetite and had to be rehydrated via IV at the vet’s office twice over a week. Poor kitty!”
We are not told what exactly caused the reaction. Perhaps it was the adjuvant.