Mostly mild side-effects reported for Pfizer's pediatric vaccine: U.S. CDC study

Toronto -

A study from the U.S. Centers for Disease Control and Prevention (CDC) has found that the nearly all of the side-effects for the Pfizer-BioNTech COVID-19 vaccine for children five to 11 years of age have been mild.

The CDC analyzed data from the Vaccine Adverse Event Reporting System (VAERS), the U.S.'s national vaccine surveillance system, as well as v-safe, a voluntary smartphone-based reporting system for vaccine side-effects.

The v-safe data found that injection site pain, fatigue and headache were the most frequently reported reactions, with fevers being more common after the second dose, between Nov. 3 and Dec. 19, 2021. Eight million doses of the pediatric vaccine had been administered to children in the U.S. during this time.

• Newsletter sign-up: Get The COVID-19 Brief sent to your inbox

There were 4,249 reported adverse effects through VAERS. Of the reported adverse effects, over 97 per cent were non-serious events, the CDC said.

Most of these events were related to vaccine administration errors, such as an incorrect dosage. Pfizer's pediatric vaccine is supposed to contain a smaller dose compared to the vaccine authorized for older children and adults.

Fever and vomiting were the most common conditions among the 100 reports of serious events.

There were also 11 cases of myocarditis, a rare side effect of mRNA vaccines that causes inflammation of the heart muscle. Of these 11 children, seven have recovered and four were recovering.

Pfizer's vaccine for children ages five to 11 was approved in the U.S. on Oct. 29. In Canada, the vaccine was given the green light on Nov. 19.

As of Dec. 17, Heath Canada and the Public Health Agency of Canada have received 60 reports of adverse effects from the pediatric vaccine. Of these events, 53 were non-serious and seven were serious. A total of 988,597 doses for children ages five to 11 had been administered as of Dec. 18.