What you need to know about COVID vaccines for young children

Here is an overview of some of the factors that should be considered in this decision regarding the later age groups that are not yet covered by previous US regulatory approvals for COVID-19 vaccines.


Moderna has submitted an application to the FDA for approval of a two-dose regimen of its vaccine, called Spikevax, for children aged 6 months to 6 years. Pfizer has not yet finalized its application for FDA approval, but its clinical trials have tested a three-dose treatment of the vaccine for children aged 6 months to 5 years.

Moderna plans to use a dose of 25 micrograms in this age group, lower than the 100 micrograms used for the first two doses for adults and the 50 micrograms used as a booster dose for non-immunocompromised adults. In its clinical trial, Moderna administered the two doses at 28-day intervals.

Pfizer and BioNTech’s vaccine, called Comirnaty, has been tested as a 3 microgram formulation for children under 5 years, as opposed to the 10 microgram version used for children 5 to 11 years old and a dose of 30 micrograms used for people 12 years old. of age and older. In their clinical trials, children received the first two doses at approximately three-week intervals, and the third dose was given at least three months after the second.

Lower dose versions should reduce the side effects associated with vaccines.


For the Moderna vaccine, in a clinical trial involving approx. 6,700 children, the efficacy for the prevention of symptomatic infections in children aged 6 months to 2 years was 43.7%, while the effect was 37.5% for children aged 2 to 6 years.

There have not yet been enough symptomatic cases of COVID-19 among children in the Pfizer-BioNTech trial to give a definitive effect number. An initial analysis based on 10 symptomatic cases of COVID-19 identified when the Omicron coronavirus variant was predominant indicated a vaccine efficacy of 80.3% in children under 5 years of age. Pfizer and BioNTech plan to update these figures after at least 21 children in the trial received symptomatic COVID-19.


Safety data, which included 1,678 children in the Pfizer study, showed that adverse reactions were generally comparable to those seen in adults. Pfizer said it chose the low-dose version of 3 micrograms because of its safety profile. Although she did not disclose specific safety data, she said the vaccine in this strength was generally as safe as the placebo used in the study.

Modern data showed that the possible side effects were mostly mild to moderate, with a fever temperature similar to that experienced after vaccination with other pediatric vaccines. A fever above 104 degrees Fahrenheit was observed in 0.2% of children aged 2 to 6 years and in those aged 2 months to 2 years.

Moderna said no reports of myocarditis or pericarditis, types of myocarditis associated with mRNA vaccines in rare cases in young men, have been reported in the trial.

The U.S. Centers for Disease Control and Prevention said, based on Pfizer vaccine data, that the incidence of heart inflammation was much lower in boys ages 5 to 11 than in teens and young men.


If vaccines obtain regulatory approval in these age groups, parents must decide whether they want their children vaccinated. One question they can ask is whether it is worth it, given that many young children became infected during the Omicron wave. According to experts, the natural immunity weakens over time. Data showed that in older children and adults, those who had been infected and received a booster shot had the greatest protection against COVID-19, according to Dr. Matthew Harris, Pediatric Emergency Physician at Northwell Health New York.

Vaccines also protect against hospitalizations and deaths, Harris said, citing these important reasons why parents should consider getting their children vaccinated.

The FDA has set June 15 as the revision date for licensing Moderna and Pfizer / BioNTech vaccines for these age groups.

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