Is the Lower-Dose COVID-19 Vaccine OK for my Child? - Nemours Blog


Is the Lower-Dose COVID-19 Vaccine OK for my Child?

Is the Lower-Dose COVID-19 Vaccine OK for my Child?

This week brought big news for kids and families. The Pfizer COVID-19 vaccine is finally authorized for kids ages 5 to 11 years. The vaccine has been studied in thousands of kids in this age group and has been found to be safe and effective. It is given as two shots, spaced three weeks apart.

The main difference between the vaccine for kids younger than 12 and those older than 12 is the dose, which is lower for younger children than for teens and adults. Studies have shown that younger kids have very strong immune systems that react just as well to lower doses of certain vaccines. An added bonus of lower dosing is that it can result in fewer side effects following the vaccine (such as chills and fever).

Parents Have Questions About Vaccine Dose

The lower dosage for younger children has confused some parents. They might wonder whether their 11-year-old should wait until they turn 12 to get the higher dose; or whether their very large 10-year-old should get the same dose as their small 13-year-old.

The experts have answered: the COVID-19 vaccine dose is based ONLY on a person’s age and NOT on their weight or height.

The size of a child matters for certain medicines that need to reach a specific concentration in the blood in order to work properly and safely. In those cases, the amount of medicine given will depend on the size of the child. Heavier or taller kids may need a higher dose. But vaccines don’t need to reach a specific concentration in the blood. They work right where they are injected, by teaching the body’s immune system to create antibodies that will recognize and fight the virus.

Most younger children have a stronger immune system than teens and adults. They can get a lower vaccine dose and still produce the same amount of antibodies as older people. A small 10-year-old and a large 10-year-old will both have this super-strong immune system, and therefore will need the same lower dose. Scientists tested a few different doses for the younger group and chose a dose that is one-third the amount given to teens and adults.

Why Waiting Is Not a Good Idea

If your child is eligible to get the shot now, do it as soon as possible rather than wait for your child to turn 12, because:

  • You will be protecting them now instead of later. As long as they are unvaccinated, they are at risk of getting infected while they wait.
  • You will be protecting others. Fewer people will be exposed to your unvaccinated child, who is at risk of getting infected during the waiting period.
  • Scientific studies have shown that the lower dose for children under 12 is very safe and very effective. And results in less side effects.
  • Vaccinating the large group of children ages 5 through 11 can bring us one step closer to ending the pandemic.

Learn More

Have questions about the COVID-19 vaccine? Find answers here.

Elana Pearl Ben-Joseph, MD, MPH

Elana Pearl Ben-Joseph, MD, MPH is a general pediatrician and a medical editor at Nemours KidsHealth.