Q: My child was vaccinated yesterday at 6 PM and now has a 38°C fever. Is this normal, or should we go to the hospital?

Medically reviewed by Sang Hyun Ahn, MD

This post is a dramatization of a question and answer session experienced by our actual medical reviewers. Please note that this content is for informational purposes only and does not constitute medical advice. Always consult with a qualified healthcare professional for any health concerns or before making any decisions related to your health or treatment.

Question:

We got my child vaccinated yesterday evening around 6 PM. It is now the next day, and my child's temperature is 38°C. Can this fever still be considered a normal reaction to the vaccination, or should we go back to the hospital?

Answer:

You must be worried about the fever the day after the vaccination.

【Current Situation】

A fever of 38°C about 18 hours after yesterday evening's vaccination → It is highly likely a normal post-vaccination reaction.

【What to Do at Home Now】

• Offer water, breast milk, or formula frequently.

• Dress the child in light clothing and maintain a comfortable room temperature.

• Consider giving a fever reducer if the child is uncomfortable (If you tell me their age and weight, I can guide you on the proper dosage).

• Redness or swelling at the injection site is common; you can gently apply a cool, damp towel to the area.

【If Any of the Following Apply → Contact the Pediatrician Today】

• The fever lasts for more than 48 hours.

• The child is extremely lethargic, eating poorly, or has not urinated for more than 8 hours.

• The child seems to have difficulty breathing or their lips turn blue.

• The injection site swells significantly or discharges pus.

【Reassurance Point】

A mild fever and fussiness within 24 to 48 hours after vaccination are common. If the child is generally playing well and staying adequately hydrated, it is safe to just observe them at home.

If needed, I can guide you on the fever reducer dosage, so please let me know your child's age and weight.

For extra peace of mind and clear guidance when tracking your child's symptoms, the FeverCoach app is always there to help.

https://fevercoach.us