A new study shows the Pfizer vaccine is safe and highly effective against COVID-19 in children as young as 6 months old.
A three-dose series of the Pfizer COVID-19 vaccine was 73% effective at preventing symptomatic COVID-19 in children aged 6 months to 4 years, the researchers found. They also found that an examination of reactions and safety results “did not suggest any concerns.”
The study, published in the New England Journal of Medicine, included 1,776 children aged 6 months to 2 years old, and 2,750 children aged 2-4 years. Children were randomly assigned to receive either the three-shot series of the Pfizer vaccine or placebo shots. Participants received the first dose of the vaccine by March 31, 2022, and lived in Brazil, Finland, Poland, Spain, or the United States.
The authors wrote that having safe and effective COVID vaccines for young children is important to protect them from hospitalization or death and because young children play a role in spreading highly transmissible variants of the virus. COVID hospitalizations for children under 5 years old peaked at a rate of 14.5 per 100,000 in January 2022, the authors wrote, noting that the Omicron virus variant appeared to affect young children more severely than the previous variant, Delta.
When the researchers evaluated vaccine effectiveness by age group, they found that it prevented symptomatic COVID in 75.8% of children aged 6 months to 2 years, and in 71.8% of children aged 2-4 years.
Less than 0.5% of participants reported severe reactions to the vaccine. The most common reactions reported were tenderness or pain. Reactions typically appeared within the first couple days following vaccine administration and resolved within 2 days. No cases of inflammation of the heart muscle or its lining were reported among participants.
Uptake of COVID vaccines for young children has been lower than other age groups in the United States. The Centers for Disease Control and Prevention says 10% of children younger than 5 have received at least one dose of a COVID-19 vaccine, and 5% have completed a primary vaccine series.
A version of this article originally appeared on WebMD.com.