"Ask the Expert" articles provide information and insights from MSU scientists, researchers and scholars about national and global issues, complex research and general-interest subjects based on their areas of academic expertise and study. They may feature historical information, background, research findings, or offer tips.

Rebecca Schein, a doctor of pediatric infectious diseases at Michigan State University, answers questions about the new FDA-approved COVID-19 vaccine for children under age 5. 

Why should I vaccinate my child against COVID-19?

Since the start of the pandemic there have been over 2.5 million cases of COVID-19, 200,000 hospitalizations and almost 500 deaths in children under 5 years of age. Vaccinating your child protects against severe COVID-19 disease, hospitalization and death. Children are also at risk for multisystem inflammatory syndrome or MIS-C, which is a severe immune response. The vaccine proved to be 99% effective in preventing MIS-C in older children. As new COVID-19 variants arise, the rate of COVID-19 infection is increasing in young children, and vaccination is the best way that we can keep them safe.

What is the difference between the vaccine for children ages 5 and under versus older children or adults?

Moderna and Pfizer-BioNTech both have approved vaccines for children over 6 months of age. The Moderna vaccine was approved at ¼ of the adult dose for children 6 months to 5 years of age and ½ of the adult dose for children 6-11 years of age. Pfizer-BioNTech makes a vaccine for children 6-11 years of age that is already on the market and now has approval of the vaccine for children 6 months to 5 years of age that is ¹/₁₀ of the adult dose. 

How will this vaccine be given?

The Moderna vaccine is a two-shot series given a month apart, with a third vaccine for children who are immunocompromised. The Pfizer-BioNTech vaccine is a three-shot series with the first two doses given three weeks apart and the third dose given eight weeks later.

Which vaccine should I give my child?

The vaccines are fairly equivalent, and whatever vaccine is available in your area would be recommended. According to the FDA, the Moderna vaccine was 50% effective in preventing COVID-19 in children 6 months to 23 months of age and 36% effective in children 2 to 5 years of age, while the Pfizer-BioNTech vaccine was as effective as the adult vaccine but requires a third dose.

What are the main side effects of the vaccine?

Vaccine side effects are very similar to the side effects of other childhood vaccines, with injection site reactions like pain, redness, swelling and some local swollen lymph nodes being the most common symptoms reported. Fever, irritability, headache and muscle aches have been described. Side effects typically last less than 48 hours. 

Will my child need additional vaccine doses in the future?

As of now there is no recommendation for additional vaccine doses, but this could change if new COVID-19 variants emerge.

What should the take-home message be about vaccination against COVID-19 for young children?

Vaccination is now available for children 6 months of age and older. The vaccine is safe and effective in preventing severe disease, COVID-19 hospital stays and death. Vaccinating your child is the best way to keep your child safe as COVID-19 rates continue to rise and fall, and new vaccine variants emerge.