Baby Vaccine Reactions: Normal vs Worry Signs | Parenting Hub
Mild fever, sore leg, more unsettled — what's normal after baby vaccines, what helps, and when to call.
Most babies are a bit unsettled, mildly feverish or sore at the injection site for 1–2 days after vaccinations. Here's what's normal, what helps, and the rare red flags.
Common (and expected)
- Mild fever (under 38.5°C) for 24 hours
- Soreness, redness or small lump at the injection site
- Unsettled, sleepy or grizzly for a day or two
- Reduced appetite, more night waking briefly
What helps
- Extra breast/formula feeds and cuddles
- Cool cloth on the injection site (not ice)
- Light clothing, cool room
- Paracetamol for discomfort if needed (not routinely)
- Don't restrict normal sleep — baby will catch up
MMR-V (12 and 18 months)
These can give a delayed reaction 5–12 days later: mild fever, mild rash and a bit unsettled. Not contagious and not a sign of measles or chickenpox.
When to seek help
- Fever >40°C or lasting more than 48 hours
- Persistent inconsolable crying for >3 hours
- Floppy, pale, unresponsive episode (HHE) — see GP
- Swelling/redness spreading beyond the joint
- Difficulty breathing, facial swelling, widespread hives — 000 (anaphylaxis is extremely rare)
Common questions
Should I give paracetamol before vaccines?
No — current advice is not to give pre-vaccine paracetamol routinely, as it may slightly reduce immune response. Treat reactions if they happen.