Side Effects of vaccines/boosters?

I posted this AM about Howie on the Lev/Lantus forum at https://www.felinediabetes.com/FDMB/threads/4-3-howie-amps-234-3-219-4-179.245653/

I’m trying to figure out why he’s not feeling good and had a big spike in his BG late yesterday/last night which is affecting his appetite and energy today. He wants to eat but only nibbles until I literally hold his dish up in front of him. He did get his annual vaccines/boosters (rabies, leukemia, etc) at his wellness check up yesterday at the vet. I’m wondering if he is feeling side effects of those possibly (like humans)? Has anyone else noticed that? I checked for ketones and he’s negative.

 

I have seen one or two cats feel off after their shots. Neko's rabies vaccine always put her off. She stopped getting shots once she was diabetic so don't know how it impacted her BG.

 

I’m going to chalk it up to his boosters/vaccines as nothing else makes sense. When I got him last March and he got his first rounds (with me), he hadn’t been diagnosed with FD. Perhaps it’s sympathy side effects with my COVID vaccine side effects! Thanks, Wendy!

 

One of my kitties was a bit off after her vaccines. I don't think it's that unusual.

 

Pabay is poorly for 2.5 days after jabs and 36 hours after wormer. He does not have a rabbies vaccine as we are in the UK. He is underweight and I think that contributes to the impact.

 

After Tyler got his rabies and Distemper shot his BG was a little bit higher for about
2 days then back to all greens. He's been in remission since 1-24-21 and I was worried when I saw the low blues.