COVID-19 Vaccine Information

(Updated 7/2/22)

COVID-19 vaccinations are the best way to prevent severe symptoms in you and your family.

The FDA has approved under EUA (emergency use authorization) Moderna and Pfizer COVID vaccines for children ages 6 months through 4 years. The CDC now recommends all children 6 months of age and older get vaccinated. 


The Moderna vaccine is a 2-dose series. The two doses are given 4 weeks apart for kids ages 6 months through 5 years. 

The Moderna vaccine was 51% effective in preventing COVID infection in children ages 6-23 months. In children ages 2-5 years, it was 37% effective in preventing COVID infection. 


The Pfizer vaccine is a 3-dose series for kids ages 6 months through 4 years old. The second dose is administered 3 weeks after the first dose and the third dose is given at least 8 weeks after the second dose. 

The Pfizer vaccine did not provide much of an immune response after two doses, so the study was continued to include a third dose. After the third dose, it was 80% effective in preventing COVID infection. However, the sample size in the study was too small for this estimate to be reliable. 

Note: The Moderna vaccine provides protection after 6 weeks (2 weeks after the second dose). The Pfizer vaccine provides protection after 13 weeks (2 weeks after the third dose). 

Both vaccines were demonstrated to be safe with possible side effects of irritability, pain, redness or swelling at the injection site, and fever. 


FAQ's :

Why should children in this young age group be vaccinated? 

Children under 5 have had the highest hospitalization rate among children who have been infected with COVID. As we have seen with the older kids, vaccination reduces the risk of severe infection, hospitalization, and complications such as MIS-C (Multisystem Inflammatory Syndrome in Children). 

Should a child who has already had COVID get the COVID vaccine? 

Yes. Immune protection from infection may not be long-lasting and reinfection can occur.  

How long should my child wait after having COVID before getting a COVID vaccine? 

We recommend waiting at least a month to make sure the infection has resolved, and no complications arise. Since there is likely to be some short-term immunity, it is ok to wait up to 2-3 months before getting vaccinated. 


Where can I get my child vaccinated? 

We have the Moderna vaccine for children ages 6 months to 5 years here at Blue Fish Pediatrics. Call our office at 314-966-8500 to schedule a vaccine appointment for your child.

WashU/BJC has vaccination sites for the Moderna vaccine for children 4 and under. Locations include the Children's Specialty Care Centers in both West County and South County. They continue to offer the Pfizer vaccine for children 5 and older. BJC COVID vaccines

Walgreens vaccinates children 3 and over. They are offering Pfizer and Moderna vaccines for children under age 5, depending on the location. They will continue to offer Pfizer vaccine to kids 5 and older.

CVS vaccinates children 18 months and older at their MinuteClinics. They are administering Pfizer vaccine.

Information for other vaccination sites can be found at:


Booster doses are recommended for everyone 5 and older. To help you determine the time to get your booster vaccines, go to the CDC booster tool linked here: When to get a booster


Below are links to address some common questions regarding COVID-19 vaccines:

Ask the pediatrician: COVID-19 questions and answers

The Science Behind the COVID-19 Vaccine

How mRNA vaccines work

How mRNA COVID-19 vaccines were developed