My five month old has just had his 16 week immunisations this morning (v late due to numerous colds etc.), I'm slightly concerned because he's been sleeping so much since! He took a two long naps this afternoon, and fell asleep shortly after 5pm, woke for a for a brief while and feed at around 7pm and has been asleep since. This is very unusual for him, he'll usually have a nap around 5pm, but will then be awake until bedtime which is 9-10pm depending on him. Do babies usually sleep a lot after immunisations? I'm not sure if it's cause for concern or if I'm just being a paranoid mum.