COVID-19 Vaccine for Kids Under 5

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With children 6 months to 4 years old now eligible for the COVID-19 vaccine, Lurie Children’s pediatrics and infectious diseases experts are answering common questions, concerns and misconceptions for impacted parents and caregivers with kids in this age group. Nina Alfieri, MD, MS and Jennifer Kusma, MD, MS, Advanced General Pediatrics and Primary Care, and Larry Kociolek, MD, MSCI, Infectious Diseases; Medical Director, Infection Prevention and Control, provide clarity below.

Why should children under 5 get the COVID-19 vaccine?

While COVID-19 has primarily and more severely impacted adults to date, children have also been impacted medically and socially. In fact, there have been over 40,000 COVID-related child hospitalizations since the beginning of the pandemic – many with no prior medical history – and COVID-19 is now the fourth leading cause of death for those under 1 years old and fifth leading cause of death for those 1-4 years old.

COVID-19 is associated with complications in children such as long COVID, type 1 diabetes and MIS-C (multisystem inflammatory syndrome in children) which is a serious condition where different body parts can become inflamed, including the heart, lungs, kidneys, brain, skin, eyes, or gastrointestinal organs. In addition to these complications, COVID-19 infection in children can lead to mild-to-moderate illness symptoms such as fever, muscle aches and decreased appetite, for example, that can be either lessened or prevented with vaccination. COVID-19 infection also results in missed school days (and missed playdates!) for children and missed work days for caregivers. We highly encourage all eligible families to get vaccinated because we know that the available vaccines are safe and effective in preventing hospitalization and COVID-19 complications.

Moreover, most kids under two years old are not recommended to wear face masks as a preventative measure. With the pandemic ongoing, many other risk reducing strategies such as masking and distancing have been lifted to allow for more social interaction, making vaccination the optimal long-lasting protective measure. As pediatricians we – like parents – know the importance of kids being able to interact socially, play on playgrounds, and hang out around one another, and the safest way they can continue to do so amidst rising and falling COVID-19 cases in the upcoming months and years is by being vaccinated, which is the best way to ensure that they have lasting protection.

How effective is the COVID-19 vaccine for kids under 5? And between Moderna and Pfizer?

The CDC recommends Moderna or Pfizer vaccines for this age group. Both vaccines are safe and effective. Lurie Children’s will be offering only Moderna to children younger than 5 years old because Moderna is a two-dose primary series, compared to the Pfizer three-dose primary series. We will continue to offer Pfizer to those age 5 years and older.

The open scheduling link is live now on Lurie Children’s website, allowing families to schedule appointments for the COVID vaccine.

Should families choose the Moderna or Pfizer vaccine for their child under 5?

We recommend that parents and caregivers seek out whichever vaccine first becomes available to their child, since both vaccines have been shown to meet safety and efficacy standards and are excellent choices for providing immunity against COVID-19 for children. Parents and caregivers can reach out to their pediatrician with specific questions or concerns regarding their child.

How many doses are needed for children under 5? Why are they different?

Like most routine childhood vaccines, the COVID-19 vaccine requires multiple doses to reach immunity. The Pfizer vaccine requires three doses (three injections), and the Moderna vaccine requires two doses (two injections). Three doses of Moderna are recommended for moderately to severely immunocompromised children.

Both vaccines have great safety data, and as long as a child completes the entire series for either vaccine, they will become protected in a way that the FDA, the Advisory Committee on Immunization Practices (ACIP) and the CDC deem adequate. We will also continue to monitor safety to identify any potential very rare side effects.


  • Dose 1
  • Dose 2, given 4 weeks after Dose 1
  • (Only for immunocompromised children: Dose 3, given 4 weeks after Dose 2)


  • Dose 1
  • Dose 2, given 3 weeks after Dose 1
  • Dose 3, given at least 8 weeks after Dose 2

What are the potential side effects this age group might experience?

The COVID-19 vaccine side effects in children less than 5 years old are mild and similar to those from other childhood vaccines. Similar to other vaccines, kids might experience redness or soreness at the injection site (thigh or arm), increased sleepiness or fussiness, decreased appetite, swollen lymph nodes in the armpits or groin, and fever. In children over two years old there may be vomiting, headache, muscle pain, or diarrhea. These side effects tend to be mild and they self-resolve within 2-3 days, and can be treated with doses of pain relief medication that your pediatrician can recommend.

Will this age group eventually need a booster?

Recommendations for boosters in all other age groups have been announced after observing COVID-19 trends following initial vaccinations. We anticipate that the need for boosters in kids 6 months and above will be studied and evaluated over the next six months.

Where can families go for more information?

We recommend checking out the CDC website, resources from the American Academy of Pediatrics and your pediatrician’s office for more information on COVID-19 vaccines for your child.

For more information on vaccine appointments available at Lurie Children's, visit our COVID-19 vaccine page.

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