Study Finds Mild to Moderate Adverse Effects From Pfizer Vaccine in Youth at High Risk of COVID-19 Complications


The data represent teens most likely to benefit from the vaccination and are meant to offer reassurance to parents and clinicians, even with small study numbers.

A new study from the Archives of Disease in Childhood found that the adverse effects (AEs) of the Pfizer-BioNTech vaccine against COVID-19 are likely to be mild to moderate and clear up quickly in 12- to 15-year-olds at high risk of complications from the infection because of certain co-existing conditions.

The data represent teens most likely to benefit from the vaccination and are meant to offer reassurance to parents and clinicians, even with small study numbers, according to the study authors.

Although healthy children with COVID-19 infection generally have a mild illness, some coexisting conditions, such as neurological conditions, are associated with severe disease. The high-risk children were then protected to reduce their risk of infection and would not have been included in the early vaccine safety studies.

Because there were unknown AEs of vaccination in the group, the study authors requested that the parents of 27 of these children report any AEs of subsequent COVID-19 vaccinations for each child. The children were between 12 and 15 years of age, 16 of whom were male and 21 were white, with 3 hospital inpatients. They had neurological conditions, such as cerebral palsy, and a range of coexisting medical conditions, such as epilepsy and immune deficiency, for which they were receiving drug treatment of various kinds, according to the study authors.

Reported AEs all were mild to moderate except for 1 child who experienced severe fatigue and discomfort combined with increased agitation. Further, 1 family reported that seizure type changed to clusters, but this was resolved in a week.

After the first dose, there were 8 events in 6 children, which were resolved within 72 hours. These symptoms included mild rash, headache, diarrhea, presumed sore throat, neck pain, difficulty sleeping, and low blood glucose. After the second dose, 8 additional events occurred in 5 children: diarrhea, vomiting, armpit swelling, and blisters around the mouth.

In addition, paracetamol use after the first dose was high and fever was more common than reported in studies of adults; however, all recorded AEs cleared up within a week, according to the study authors.

“Numbers were small, but these data are especially important as they are representative of the children who are most likely to benefit from vaccination, and parents and clinicians may have concerns regarding an increased risk of unexpected events,” the study authors said in a press release. “The parents choosing to take up this vaccination at a time when it was off-license, with little available safety data, did so because they [and their clinicians] believed their children to be at high risk of COVID-19 disease. Indeed, many had been shielding and felt that vaccination would make a significant difference to their lives.”


Pfizer jab side effects in 12-15 year olds at high risk of COVID-19 complications, mild to moderate. EurekAlert! August 26, 2021. Accessed August 27, 2021.

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