10 week baby not himself after 1st vaccine dose

[Twoheartsonemama]

Hi everyone,

My baby received his first set of vaccines about 10 days ago, along with the oral rotavirus drops. He’s exclusively breastfed. Since then, he hasn’t quite been his usual self:

• More drowsy than usual
• Reduced appetite / feeding less often
• Weight gain has slowed — he was consistently gaining 200–220 g/week, but in the past 8 days has gained only 110 g
• Congested nose
• For about 6 days after the vaccine, he also had very large, frequent watery stools with mucus

We went to the doctor, and they said it’s okay since he has enough wet nappies and otherwise seems fine.
But now that it’s been over a week, I’m starting to get a bit worried.

Has anyone else experienced something similar with their baby after the first vaccines or rotavirus drops?
Would really appreciate hearing your experiences or reassurance.

This is a normal reaction to the vaccine I would say. Rotorvirus is nasty and the vaccine gives a taste of it (imagine getting the full blown thing!) if still producing wet and dirty nappies, no huge temps and baby is waking ok then it sounds all ok. But if worried go back.

It's all very normal, especially the dodgy nappies after the rotavirus dose.

You should really only be weighing your baby once a month (maximum) at this age though. There will always be weeks where baby doesn't gain much, or growth will slow. The important thing is the trend they're showing.

@LuckyNumberFive @Tiebiter - thank you for the response, that is reassuring. How long do you think this is going to last ? Mainly concerned about loss of appetite or willingness to feed, also worried my supply will dip if he continues to feed so less?

Loss of appetite is also normal, just like when we aren't feeling well we might be off our food a bit. My first was a bit iffy for 10-14 days after. The first set of jabs were definitely the worst for us. If you're worried about your supply you could pump, but I found as long as baby was still feeding a bit my supply bulked back up when needed. Offer the breast often and just see what happens.

If you're concerned there's probably an infant feeding team in your area, give your HV office a call, but I've always written off the first two weeks post-jab period as a bit up and down. As long as there wasn't a fever that wouldn't come down I'd just take it day by day.

Just FYI, around 12 weeks your baby will suddenly become a more efficient feeder and feeds often become shorter and/or more spaced out. I was worried my baby was on nursing strike - nope, they could just do a full feed in 10 minutes and go 3h between some feeds! Long 30 minute feeds only happened in the middle of the night for my baby from 3-6 months.

(I'm sure the change in feeding you have seen is real and related to the rotavirus vaccine, but other changes are also coming, so don't panic).

@LuckyNumberFive - thank you ! Wow , maybe I got lucky with my first. He was just off for the first 36-48 hours and back to being himself after.
@OtterMummy2024 - my one is already on really small feeds, even the first 6 weeks he would only do 10-12 mins , now it’s getting shorter which has me wrecked . But he does cluster feed evenings to make up for Those short feeds during the day !

Update for someone going through this : I found in some thread that some paediatricians recommend probiotics after rota virus vaccine .
got my LO on optibac and it seemed to normalise the poos and bring back appetite .

the vaccine did leave nasty symptoms on my LO , dreading the next dose🥲

It is much better than actually getting the diseases that the vaccine prevents though so do keep that in mind.

Both of mine were knocked around for awhile after the first vaccine. Absolutely fine after all their other doses so don’t stress about it until you need to.