According to a ProMed Mail posting on March 31st, a Phase 3 trial evaluating children aged 12 to 15 years of age in the U.S. showed a high level of protection elicited by the Pfizer vaccine. The trial comprised 2,260 subjects with vaccinates receiving the same protocol as adults in accordance with FDA Emergency Use Authorization.  Eighteen cases of symptomatic COVID were recorded in the placebo group while the children receiving vaccine were unaffected.  Antibody levels in the adolescent subjects receiving the vaccine were higher than in a previous trial with 16 to 25-year-old subjects. 

A third trial has now commenced to evaluate the protective effect of the vaccine in children 5 to 11 years of age. Subsequent trials will examine the response to vaccination in groups aged 2 to 5 years and then 6-months to 2 years.  It is hoped that vaccine will be made available to children under 12 years of age at the beginning of 2022.  Moderna is testing their mRNA vaccine in adolescents aged 12 to17 years and AstraZeneca is testing their vaccine in children 6-months and older.

Jennifer Nuzzo, an epidemiologist at the John Hopkins Center for Health Security commented, "while I don’t think we have to wait until children are vaccinated to fully reopen schools, being able to vaccine children may help some families feel safer about returning to school".

It is estimated that children represent less than one percent of COVID deaths, but two percent who become infected require hospitalization. Epidemiologists maintain that vaccination of children will be necessary to achieve herd immunity as the proportion of the population under 18 years of age represent 23 percent of the total in the U.S.