COVID-19 Vaccine
Content reviewed against published CDC, AAP, WHO guidelines
Last reviewed:
Key takeaways
- Prevents: COVID-19 (SARS-CoV-2 infection), Multisystem Inflammatory Syndrome in Children (MIS-C)
- Schedule: 3 doses starting at 6 months (primary series)
- Effectiveness: In children aged 6 months to 4 years, the primary series showed approximately 40-80% effectiveness against symptomatic infection (varies by variant) and over 75% effectiveness against hospitalization and severe disease including MIS-C.
- Most common side effect: Pain, redness, or swelling at injection site
How it works
The updated COVID-19 vaccines for children use mRNA technology (Pfizer-BioNTech or Moderna) to instruct cells to produce a harmless piece of the SARS-CoV-2 spike protein. The immune system recognizes this protein as foreign and builds antibodies and T-cells to fight the actual virus if encountered. The mRNA is quickly broken down by the body and does not alter DNA.
Recommended schedule
| Dose | Age |
|---|---|
| Dose 1 | 6 months (primary series) |
| Dose 2 | 3-8 weeks after dose 1 (depending on product) |
| Dose 3 | Updated annual dose recommended each fall |
Side effects
Common (mild, resolve in 1-2 days)
- Pain, redness, or swelling at injection site (most common)
- Irritability or crying (infants and toddlers)
- Sleepiness or fatigue
- Mild fever
- Loss of appetite
- Muscle aches (in older children)
Serious (very rare)
- Myocarditis/pericarditis — extremely rare, primarily in adolescent males after dose 2 (approximately 1-5 per 100,000 in 12-17 year old males; even rarer in younger children)
- Severe allergic reaction (anaphylaxis) — approximately 2-5 per million doses
- Febrile seizures — very rare, similar rate to other childhood vaccines
Who should NOT get this vaccine
- Severe allergic reaction (anaphylaxis) to a previous dose of COVID-19 vaccine
- Known allergy to any component of the vaccine (e.g., polyethylene glycol)
- Note: Children under 6 months are not currently authorized to receive COVID-19 vaccines
Effectiveness
In children aged 6 months to 4 years, the primary series showed approximately 40-80% effectiveness against symptomatic infection (varies by variant) and over 75% effectiveness against hospitalization and severe disease including MIS-C. Updated formulations targeting current variants provide improved protection.
Available brands
Comirnaty / Pfizer-BioNTech COVID-19 Vaccine
Pfizer-BioNTech
Spikevax / Moderna COVID-19 Vaccine
Moderna
Myths vs. facts
Myth: “The mRNA vaccine changes children's DNA”
Fact: mRNA cannot enter the cell nucleus where DNA is stored. It is read by ribosomes in the cytoplasm, produces the spike protein, and is then rapidly degraded by normal cellular enzymes — typically within 48-72 hours.
Myth: “Children don't need the vaccine because COVID is mild in kids”
Fact: While most children have mild illness, COVID-19 has hospitalized over 200,000 US children, caused over 1,800 pediatric deaths, and can trigger MIS-C — a serious inflammatory condition. The vaccine significantly reduces these risks.
Myth: “Natural immunity is better than vaccine immunity for children”
Fact: Natural infection carries risks of severe disease, long COVID, and MIS-C. Studies show that vaccination after infection provides the strongest "hybrid immunity," and vaccination alone provides robust protection without the risks of disease.
Frequently asked questions
At what age can my baby get the COVID-19 vaccine?
Can my baby get the COVID-19 vaccine at the same time as other vaccines?
How often does my child need an updated COVID-19 vaccine?
Is myocarditis a concern for babies and toddlers?
Sources
All content follows our editorial policy and is reviewed against published clinical guidelines.
2,705 evidence-based guides6 authoritative medical sources
Bottom line
The COVID-19 Vaccine (COVID-19) is safe, well-studied, and recommended by the CDC, AAP, and WHO. Talk to your pediatrician if you have questions about timing or your child's specific health needs.
Choosing to vaccinate your child is one of the most important things you can do to protect their health. If you have concerns, your pediatrician is always happy to talk through them with you.