October 22, 2021 – Pfizer Says Its Childhood Vaccine Is 90% Effective at Preventing COVID-19 Infections.
The Pfizer vaccine for children aged 5 to 11 years is 10 micrograms, about one third of the dose given to adolescents and adults.
In the data presented to the FDA prior to the agency’s review of its syringes for children, the company described the interim results of two ongoing studies testing the safety and effectiveness of its 10-microgram shots.
The data on the effectiveness of the vaccine come from a study of more than 2,000 children aged 5 to 11 years. Two-thirds of the children were randomly assigned a child-appropriate dose of the Pfizer BioNTech vaccine, while the other third were assigned to the placebo group.
The study began when the delta variant became dominant worldwide. By the first week of October, 16 participants in the placebo group had symptomatic, laboratory-confirmed COVID-19 infection, compared to only three who had contracted COVID in the vaccinated group.
According to the company’s own studies, the side effects observed in the study were almost all mild. The most commonly reported side effect was pain at the shooting site. Children in the vaccine group were also more likely to have fatigue, headache, fever, and chills than in the placebo group. These occurred most often after the second dose. Some skin reactions such as itching and rashes were seen in the study, but most of them were mild and went away within a few days.
Children could also have swollen lymph nodes after their vaccinations, as sometimes adults do, but these reactions were temporary.
One child developed a tic, a recurring involuntary muscle twitch, or a sound of a voice that occurred a week after the second dose of the vaccine. It was considered linked to the vaccine by investigators on the study. The company says it would go away by the time the study was published.
Reassuringly, no cases of inflammation of the heart called myocarditis were found in the study. Myocarditis is rare and transient but requires hospital treatment. The highest rates of myocarditis were seen in men under 30. This group has a risk of about 11 cases per 100,000 doses given, according to a study recently published in the New England Journal of Medicine.