Baby Sleeps A Lot After Vaccine, What Can I Do To Help?

The following 48 hours after immunization is challenging and discomforting for your baby. Expect changes in their attitude, like feeling extra sleepy, irritable, or running a fever. Redness at the injection site is also normal, as well as lumps under the skin that can persist for up to a week.

If your baby is extra sleepy after the shot, allow him to rest. It is a good sign that his body is fighting the virus. When your baby is unsettled and has an elevated temperature, a dose of acetaminophen helps.

There is nothing to worry about unless your baby manifests adverse and prolonged symptoms, but these are often rare.

When you have problems regarding your baby’s health, do not hesitate to contact the baby’s pediatrician. 

Understanding baby sleep patterns

Sleep in babies varies depending on their age and changes as they grow older.

Newborn infants spend most of their time sleeping. That is roughly 12 to 16 hours of cumulative sleep lasting 20 to 50 minutes per nap.

As babies grow, they gradually spend more time waking than napping. The babies’ sleep cycle change when they are two to three months old. They will develop night and day sleep, which means your baby will now sleep less during the day and longer at night.

Your baby may still wake up once at night but will have about 6 hours of sleep. 

When babies are sick with a minor illness or recently had their vaccinations, they will spend a long time napping. It helps their body to recuperate or gives them time to fight off the vax intrusion. 

The effects of vaccination on baby sleep

Routine vaccination is a global health program for children to protect them from life-threatening diseases. Health organizations administer the complete vaccine doses scheduled according to the child’s age starting from birth. 

Vaccines are the weakened or inactive part of an antigen or the subpart of viruses, bacteria, parasites, and fungi. It is introduced into the body to trigger it to produce antigens and improve the immune response.

If a particular pathogen invades the body, the immune system will respond better after its first exposure. 

Some vaccines need multiple doses given a few weeks or months apart. Catch-up vaccines are given to children who missed the required dose. Vaccines are a lifetime guarantee to provide the body with a better edge in case it is exposed to a specific pathogen in the future. 

Immunization is a mandatory global policy and a requirement for international travel. Many government health offices offer it for free.

So, make sure your baby is lifelong protected against diseases by getting him his required vax shot. 

Common side effects of vaccines

Mom is checking on her infant baby who is noticeably sleeping more after getting a vaccine shot

Vaccines do trigger responses like a run-of-the-mill fever in babies. If you are a new parent, it can be as discomforting for you. But don’t worry, the minor ailment will last for a couple of days, and your baby will be back to his usual self.

Adverse reactions to a vaccine are rare and only possible in children with underlying health conditions like cancer. 

The most common vax reactions are:

  • Sleepiness
  • Restlessness
  • Low-grade fever
  • Localized redness and swelling

Why does a baby sleep more after the vaccine?

Aside from the fact that your baby is tired after crying from the shot, sleeping is also a sign of a good immune response.

Mom is monitoring her infant baby, who is sleeping a lot more than usual

Expect them to temporarily ignore their usual sleep-wake schedule. But as long as your child wakes up to feed, he will be fine. 

Babies with fever tend to sleep longer than those who did not develop it after the shot. Fever is a side effect that you should highly anticipate a few hours after the immunization. Babies usually have axillary temperatures higher than 38.5⁰C or 101.3⁰F, lasting 24 to 48 hours.

It is a sign that his body is fighting the infection and pouring out chemicals to counter the invaders. Your baby may also become fussy and irritable, but it is not something you cannot manage. 

Like adults, sleep is the deep form of rest to help the body recover quickly. In addition, sufficient sleep helps boost the efficacy of the vaccine as the immune system works on developing antigens. 

Health experts encourage parents to let their babies take their time sleeping or napping to let them rest well. 

In a study conducted, researchers suggest letting children have afternoon immunization to increase sleep in the next 24 hours.

Accordingly, sleep duration is often longer for babies who receive their shots in the afternoon than in the morning.

Other ways to help baby after vaccination

Sleep is beneficial for your baby after the vaccine. So, provide him with a supportive environment conducive to sleeping.

Dress your baby comfortably, ensure the right room temperature, and provide a quiet room for him. If playing white noise helps, then provide it for him too. 

It is not yet the best time to enforce a strict sleeping schedule. Let your baby manage his sleeping time. Don’t fret when nap time last longer than usual.

Mom is bottle-feeding water to her infant baby to help keep her hydrated

For now, you can let them break a sleep routine as they weather the sting. Your baby will get back to his regular sleep and wake schedule after he recovers from the minor discomfort.  

Here are a few ways you can help your child after a vax shot:

  • Provide skin-to-skin contact or cuddle your baby close
  • Offer plenty of feedings 
  • Swaddle your infant
  • Rock and nurse him to sleep
  • Let him rest
  • Dress him comfortably
  • Give acetaminophen for fever as instructed
  • Give a warm compress on the injection site

After the shot, following the doctor’s instructions and at-home care is important. For babies younger than 3 months, the physician will prescribe a fever medicine according to the baby’s weight.

If you worry about symptoms after the vaccination, call your pediatrician for more information. Also, inform him if you notice these signs:

  • The fever does not go away after 48 hours with medication
  • Not waking up to feed
  • Will not feed
  • Fewer wet diapers
  • Inconsolable crying for more than two hours
  • Has a normal temperature but is still very lethargic 
  • Fast and difficult breathing


Will my baby develop keloid from a vaccine?

Any sort of skin injury can develop into a keloid, and it develops randomly in persons.

Some vaccinations may cause keloid formation, like the BCG, smallpox, and Hepa B vaccinations. It looks like a small scar that is asymptomatic and does not pose any health concerns. 

If the pathogen is used in vaccines, will it not cause the same disease to happen?

No, vaccines are made from dead viruses or bacteria or just a part of it. The amount introduced to the body is very minimal and is impossible to trigger the same illness.

Can the vaccine cause autism?

No, there is no proof that links vaccine to autism after many studies. It is similar to the myth that fever causes brain damage. 

Can I give ibuprofen instead of acetaminophen?

Ibuprofen, like Advil, is also an effective anti-fever medicine. However, it is only recommended for children older than 6 months. But do not, in any way, give aspirin to babies and children, which can cause the deadly Reye’s Syndrome.


Your baby’s pain is your pain too. You may dread vax days for the sting of seeing your little one scream in pain. But vaccines are a vital part of their lives that provide them with much-needed protection from certain diseases.

Vaccines are perfectly safe, and it works for many decades protecting people from harmful diseases. 

For further reading, you can head out to these posts for related topics:

Was this article helpful?

Ann Marie is a licensed nurse in the Philippines. She experienced handling and assisting deliveries of newborns into the world. She also trained in labor rooms and pediatric wards while in nursing school - helping soon-to-be mothers and little kids in the process. Though not a mother by nature but a mother by heart, Ann Marie loves to take care of her younger cousins as well as nephews and nieces during her free time.

Leave a Comment