So, so sorry to read about your loss, please accept our sincere sympathy.
We lost our 15 week old old puppy just over 2 weeks ago and within 24 hours of his Parvo/KC vaccination. We're absolutely heartbroken as he was our baby (never had children) and was the world to us and we loved him dearly in the short time he was with us. There's still a lot of tears, we never ever thought we'd lose him after being immunised and he'd be here to grow older with us.