Fever After Vaccination: Causes & How to Deal with It?

Fever After Vaccination: Causes & How to Deal with It?

Medically Reviewed By
Dr. Mahesh Patil (Paediatrician)
View more Paediatrician Our Panel of Experts

Once your baby is born, you have to get them vaccinated with some essential life-saving vaccinations. Vaccinations are important for babies. Vaccinations can be a tough time for parents, as they often feel helpless watching their little ones cry. However, vaccinations help prevent babies from getting life-threatening diseases and are essential. One of the side effects of vaccination is fever. As a parent, you may not know what you should do in such a situation and often feel helpless. But do not worry. We are here to help you. In this article, we have covered some important things related to vaccination for babies, including fever after immunisations. Let’s read!


Is Post-Vaccination Fever Normal?

Some babies experience a high temperature after getting a shot, and this is normal. It means that your child’s immune system is responding to the vaccination. Hence, you shouldn’t be worried if your baby is down with a mild fever.

What Causes Fever After Vaccination in Infants?

Vaccination prevents diseases from infecting the body, by preparing the immune system to fight against a potential threat. The material in vaccines is made up of organisms (viruses/bacteria) causing an infection against which protection is required or expected. These organism’s ability to cause illness in the recipient is toned down. When the vaccine enters in the body, it activates immunity cells in the body, which in response to invasion by the organisms produce inflammatory markers, which, in turn, cause swelling and tenderness at the site of injection and fever in the body. So, fever is an indication of a good immune response of body.

What Are the Red Flags?

A temperature over 99°F is regarded as fever in children and it shouldn’t be ignored. Here are the signs you should look out for:

  • 101°F or higher in babies younger than 3 months
  • 102° F or higher in babies who are between 3- and 6-months-old
  • Extreme fatigue
  • Pain in the stomach, limbs, and ears
  • Difficulty swallowing fluids
  • Vomiting or diarrhoea
  • Fever that persists for more than 3 days
  • Drowsiness

Tips to Help Your Baby Deal With This Phase

Even though a fever after vaccination is normal, you would want to ensure your baby feels more comfortable and relaxed. Here’s what you can do:

1. Be There for Her

There’s nothing more than an infant wants than her parents’ love and care. Just be there for your child. Plan the day such that you get 3 to 4 hours with your child after vaccination.

2. Don’t Layer Clothing on Your Baby

Clothe your child in light and comfortable clothes. You can also cover with a soft blanket.

3. Give Her Plenty of Fluids

Fever dehydrates the body, so make sure you give her plenty of fluids to drink.

A mother feeding her baby

4. Keep Your Infant’s Room Well-Ventilated

Keep the windows open and let the fresh air in. The ideal temperature is 18° Celsius (65° F). You can also use a humidifier.

5. Try OTC Medication

You can try over-the-counter medication like paracetamol or ibuprofen if your baby is distressed and uncomfortable. Ibuprofen is equally safe and effective in babies less than 6 months and those older than 6 months. Compared to paracetamol, ibuprofen has more side effects in babies less than 6 months. Hence, it is advisable to use paracetamol to treat fever as the first choice and if it is not effective, ibuprofen could also be used alone or in addition to paracetamol.


1. Do All Babies Have Fever After Vaccination?

Knowing that immunisation can cause a fever, sometimes parents wonder if a lack of fever means the vaccine is not working properly. However, not every baby responds to a vaccine with a fever.

2. Does Breastfeeding Reduce Fever in Babies After Vaccination?

According to studies, breastfed babies are at a lower risk of developing fevers due to vaccination. But this may not be true for all breastfed babies.

3. Does Your Baby Sleep More After Vaccination?

A baby may sleep a little extra in the 48 hours following their vaccination as they need to rest. It means that their body is doing an excellent job of fighting the virus.

4. Should You Bath Your Baby After Giving Them a Vaccine?

Yes, your baby can take a bath after vaccination.

5. How Long Can a Baby Unwell After Vaccination?

Side effects after vaccination can last one to two days.

6. Should You Give Your Child Medicine Before a Vaccination to Prevent Fever After Vaccination?

You can give your baby a fever medication before vaccination, depending on the age of your baby. Do consult with your baby’s doctor about which medicine you should give to your baby.

In most cases, a post-immunisation fever will resolve on its own. However, it’s always better to follow your gut instinct, and contact your paediatrician if you feel something amiss.


1. Immunisation – side effects; betterhealth.vic.gov.au; https://www.betterhealth.vic.gov.au/health/healthyliving/immunisation-side-effects

2. Vaccinations; cdc.gov; https://www.cdc.gov/breastfeeding/breastfeeding-special-circumstances/vaccinations-medications-drugs/vaccinations.html

3. Childhood vaccinations; skai.org.au; https://skai.org.au/childhood/your-vaccine-visit/after-your-visit

4. Vaccines at 4 Months; cdc.gov; https://www.cdc.gov/vaccines/parents/by-age/months-4.html

5. Immunization Reactions; seattlechildrens.org; https://www.seattlechildrens.org/conditions/a-z/immunization-reactions/

Also Read:

Pain After Vaccination in Infants
Painless Vaccination for Babies
Can Babies Have Vaccinations With a Cold or Cough?

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