The Pfizer-BioNTech vaccine was studied in a clinical trial of more than 2,200 children aged 5 to 11, including about 150 children at Stanford. The trial followed the same process as clinical trials used for all other childhood vaccines.
In the trial, COVID-19 vaccination produced a similar immune response to that seen in clinical trials in adults. The vaccine was 90.7% effective in preventing symptomatic COVID-19 infection in children.
Children in the trial had only mild to moderate side effects that resolved in a few days. The side effects included redness and swelling, fatigue, headache, muscle and/or joint pain, chills, fever, swollen lymph nodes, nausea and decreased appetite. These side effects are consistent with the body’s normal reactions to vaccination and indicate that the immune system is doing its job. Side effects in the heart, which have been observed in some adolescent boys who received the vaccine, were not seen in children younger than 12.
The side effects of vaccination are much less severe than the range of symptoms with COVID-19 infection. Although most children with COVID-19 have mild illness, thousands across the country have been hospitalized, and hundreds have died. Getting vaccinated is much safer than getting sick with COVID-19.
Clinical trials in children of the Moderna COVID-19 vaccine are underway.
On Nov. 2, the CDC’s Advisory Committee on Immunization Practices (ACIP) unanimously recommended the Pfizer-BioNTech COVID-19 vaccine for kids 5 to 11 years of age. Dr. Grace Lee, associate chief medical officer for practice innovation and infectious diseases physician at Stanford Children’s Health, and ACIP Chair, discusses the recommendation.