Figures about Pfizer side effects for children need more context

28 September 2021
What was claimed

86% of children suffered an adverse reaction to the Pfizer/BioNTech Covid-19 vaccine in clinical trials.

Our verdict

This figure is correct, but ignores vital context. The adverse reaction in question was pain at the injection site, an extremely common side effect for many vaccines. Most of the study participants (aged 12 to 15 years old) reported only mild or moderate pain.

A post on Instagram claims that 86% of children suffered an adverse reaction to the Pfizer/BioNTech Covid-19 vaccine in clinical trials. 

Specifically, it says that 86% suffered an adverse reaction after the first dose, with 78.9% suffering an adverse reaction after the second dose. 

These figures are correct, but are missing vital context. The image in the post itself provides a link to a fact sheet, written by the US Food and Drug Administration, for health care providers administering the Pfizer/BioNTech vaccine. 

This document clearly states that the two figures, 86% and 78.9%, relate to pain at the injection site, for example a sore arm in the days after vaccination. The vast majority of these events were described as causing only mild or moderate pain, and were reported during a study involving participants aged between 12 and 15 years old. 

Dervila Keane, global media relations spokesperson for Pfizer Europe, told Reuters that the safety of the vaccine was similar to other vaccines given to adolescents, with mostly short-term, moderate or mild side effects such as a sore arm at the site of vaccination. 

In June, the Medicines and Healthcare products Regulatory Agency (MHRA) announced that the UK approval of the Pfizer/BioNTech vaccine had been extended, meaning it could be given to 12-15 year-olds. 

Several other countries, including the US, Canada and Israel have already given universal approval for 12 to 15 year-olds to have the vaccine. 

A spokesperson for the MHRA told Reuters in July: “In the clinical trial, the safety data in children 12-15 years of age was comparable with that seen in young adults 16-25 years of age and no new side effects were identified.”

We have written before about the possible link between the Pfizer/BioNTech vaccine and myocarditis (heart inflammation) or pericarditis (inflammation of the lining around the heart)  in younger men. The MHRA said in early July that it had conducted a thorough review of reports of myocarditis after vaccination, adding that reports typically presented as mild cases with individuals recovering within a short time following standard treatment and rest. Healthcare professionals and people getting the vaccine were also advised to be aware of the signs and symptoms of the condition. 

This article is part of our work fact checking potentially false pictures, videos and stories on Facebook. You can read more about this—and find out how to report Facebook content—here. For the purposes of that scheme, we’ve rated this claim as missing context because while this figure is true and from an official source, it relates to the percentage of children who suffered pain at the injection site after vaccination.

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