Vaccinations

Co

Is it normal for bby to sleep so much after shots?

Mind got his 4 month on Thursday and since then he’s fallen asleep 7pm-3 am wakes to eat then 3:20-6:30 he falls back asleep. I tried to bathe him tonight but I couldn’t wake him! He’s just so sleepy!? Is this his way of showing a reaction to the vaccinations! Should I be worried?!