Fact Check-Pain at injection site was most commonly reported adverse reaction in 12-15-year-old vaccine recipients

Articles and social media posts online have shared the statistic that 86% of children in a COVID-19 vaccine trial suffered an adverse reaction, often without giving further details. While the statistic is taken from an authentic research document, the figure of 86% refers to reported pain at the injection site – an adverse reaction that is typically short-lived and mild to moderate, according to the maker of the vaccine.

One article entitled “Shocking 86% of Children suffered an Adverse Reaction to the Pfizer Covid Vaccine in Clinical Trial” (here ) contains screenshots of tables laying out reported adverse reactions. They were taken out from a three-page report entitled “Pfizer-BioNTech COVID-19 Vaccine EUA Fact Sheet for Healthcare Providers Administering Vaccine” (tables 5&6, p.25 here) .

The tables record solicited adverse reactions, by severity, among trial participants aged 12 to 15. The most commonly recorded local reaction was pain at the injection site. This was reported by 86.2% of participants. Most described it as mild or moderate; 1% described it as severe. Other local reactions recorded were swelling (6.9%) and redness (5.8%). A separate table recording solicited systematic reactions show fatigue and headache as the most commonly reported reactions, at 60.1% and 55.3% respectively.

Dervila Keane, Global Media relations spokesperson for Pfizer Europe, told Reuters by email: “The vaccine had a favourable safety and tolerability profile, similar to other adolescent vaccines, with mainly transient, mild-to-moderate reactogenicity, no vaccine-related serious adverse events and uncommon severe/serious adverse events.

“Reactogenicity events were typically transient and mostly mild-to-moderate, with frequencies generally similar post-dose 1 and 2 and between age groups; an exception was slightly higher incidence of fever post-dose 2 in 12-15-year-olds (20%) compared with 16-25-year-olds (17%).”

The term reactogenicity refers to adverse effects that result from the body's inflammatory response to vaccination (here , ).

On June 4, 2021, the UK Medicines and Healthcare products Regulatory Agency (MHRA) announced an extension to the UK approval of the Pfizer/BioNTech COVID-19 vaccine that would allow its use in 12- to 15-year-olds (here ).

A spokesperson for the UK Medicines and Healthcare products Regulatory Agency told Reuters by email: “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. As in the young adult age group, the majority of side effects were mild to moderate, relating to reactogenicity (eg, sore arm and tiredness). As stated in the Product Information (here), the most frequent adverse reactions in children 12 to 15 years of age were injection site pain (> 90%), fatigue and headache (> 70%), myalgia and chills (> 40%), arthralgia and pyrexia (> 20%).”

In a news release on the MHRA website (here), Dr June Raine, MHRA Chief Executive, said that examination of the available clinical data had allowed the agency to conclude the benefits of the vaccine outweighed any risk for the 12-15 age group.

In the same news release, Professor Sir Munir Pirmohamed, Chair of the Commission on Human Medicines, said the MHRA would “continue to scrutinise all of the suspected side effects data received through the rigorous surveillance programme in place through the Yellow Card scheme (here) and other safety surveillance measures for all of the COVID-19 vaccines used in the UK.”

While adult vaccine rollout is underway in many parts of the world, as shown by Reuters Vaccination Tracker (here ), the question of whether to vaccinate children is one that is still being studied by many health authorities. European countries are still deciding whether and when to inoculate children against COVID-19 amid questions around safety, supply and the desperate call for more vaccines from hard-hit regions around the world (here ).


Missing content. The figure of 86% relates to “pain at injection site”, which is a frequently recorded reaction to vaccination that is typically short-lived and mild to moderate.