New data shows Pfizer vaccine safe for children

The Medicines and Healthcare Regulatory Agency (MHRA) approved the Pfizer Covid-19 vaccine for use in children (aged 5-11) just before Christmas. The MHRA is responsible for approving all medicines and medical devices in the UK.

The MHRA conducted a detailed review of the available evidence in late 2021. It concluded that the overwhelming majority of reported side-effects were incredibly mild. Of the reported side effects in children, nearly all were tenderness at the injection site and mild flu-like symptoms.

Why should children be vaccinated?

Although Covid-19 is usually milder in children than in adults, rare but serious illness and long-term complications (such as multi-system inflammatory syndrome, MIS-C) do occur. A study in America in 2021 showed that 0.3% of cases would develop into MIS-C. That is a low number, but even a small percentage of a high number can itself be a very high number.

School-age children have represented a high proportion of Covid-19 cases worldwide. They may also play an important role in the transmission of the virus across communities.

Many children have also had their education, social and emotional development adversely affected by the pandemic. Safe and effective vaccines are therefore needed to help mitigate risks for children and society.

Now a study published last week has provided more evidence that the Pfizer vaccine is safe and effective in children.

An international study

The study led by Pfizer and BioNTech is scheduled to run until 2026, although it is initial data that has been published. The data has been peer-reviewed and can therefore be viewed as accurate.

The study is tracking over 11,000 patients across the USA, Finland, Poland and Spain. The proportion of those aged between 5-11 includes 2,268 children. They were assigned into groups receiving either vaccination or a placebo on a 2:1 basis (1,517 received the vaccine and 751 received a placebo).

The subjects were reviewed just two months after vaccination and Pfizer vaccine had a favourable safety profile. No vaccine-related serious adverse events were noted.

The effect of the vaccine on children

The vaccine stimulated a strong immune response. Among participants (who had no evidence of previous infection) there were three cases of Covid-19 among the vaccinated recipients and 16 among placebo recipients. The vaccine was shown to be 90.7% effective at preventing Covid-19 related illness.

Recipients of the Pfizer jab reported more local reactions than placebo recipients. However, the reactions were generally mild to moderate, lasting 1 to 2 days. Injection-site pain was the most common local reaction, occurring in up to 74% of Pfizer recipients.

Severe injection-site pain was reported in 0.6% of vaccine recipients and in no placebo recipients. Fatigue and headache were also frequently reported, although frequencies of fatigue, headache, and chills were similar among vaccine and placebo recipients after the first dose. However, they were more frequent among vaccine recipients than among placebo recipients after the second dose.

The most serious adverse events reported from the Pfizer jab were 10 cases of Lymphadenopathy, a swelling of the lymph nodes or glands. One case was also reported amongst the placebo group. All recovered quickly.

No myocarditis, pericarditis, hypersensitivity or anaphylaxis was reported amongst the vaccine recipients. No deaths or adverse events leading to withdrawal from the study were reported.

Will more children be offered the vaccine?

The Joint Committee on Vaccination and Immunisation (JCVI) has already recommended that children agreed 5-11 who are in a clinical risk group, or have household contacts with immunosuppressed people should be offered the Pfizer vaccine.

It is for the JCVI to make the decision on whether to extend the vaccine to all 5-11 year olds, as well as provide the final recommendation any dosing interval between jabs.

The JCVI has stated that it is reviewing data about the number of 5 to 11 years who have already been infected, the level of protection to Omicron arising from previous infection, adverse-event reporting from Pfizer (such as the data just published) and a review of the potential impacts of vaccination on education.

The data just released shows that there are very few known risks to vaccinating children aged 5-11 with the Pfizer BioNTech vaccine. A decision from the JCVI is expected in the coming weeks.