Two Covid jabs DON’T raise risk of myocarditis in English youngsters, real-world data shows

There is not an increased risk of heart inflammation from Pfizer’s Covid vaccine in British adults and older teenagers, the world’s biggest study into the issue suggests. 

Analysis by the universities of Edinburgh and Oxford said myocarditis was occurring at a rate of three per million jabs administered in people aged 16 to 40.

They said this was not significantly different to the rate in the general population for the same age group. 

Reports of myocarditis in young people and teenagers in other countries early in the rollout complicated the debate on whether British children should be jabbed. Data from Israel and US — where the dosage gap is only three weeks — suggested the condition was more common. 

Experts believe Britain’s 12-week spacing has cut the risk of myocarditis and helped keep numbers low.

Scientists described the data as ‘reassuring’ to young people. But because the data did not look at young people specifically, questions on incidence in teenagers unanswered. 

All over-12s are now eligible for Pfizer’s vaccine after the Government U-turned on the roll-out and signed off on jabs for children. 

The Joint Committee for Vaccination and Immunisation — the independent group advising ministers on vaccine policy — is now locked in discussions on whether to recommend vaccines to children as young as five.

Professor Lim Wei Shen, chair of the panel, today hinted the decision will be made before Christmas. 

Vaccinating young children still makes many scientists uneasy due to the tiny risk the virus poses to them.

No10’s advisers were originally unconfident on approving them because the benefits did not clearly outweigh the risks, with youngsters unlikely to fall serious ill or die with the virus.  

Researchers from the Universities of Edinburgh and Oxford found there were no cases of the ultrarare heart inflammation per million second doses of either Pfizer’s (labelled BNT162b2 above) or AstraZeneca’s (ChAdOx1) vaccines across all age groups. In under-40s, Pfizer’s jab caused two excess admissions per million after first doses and three per million after second doses

Graph shows: Hospital admissions for myocarditis, pericarditis and cardiac arrhythmia from April 2019 to October 2021. Myocarditis admissions have been declining throughout 2021 and are not substantially higher than before the start of the vaccine rollout

Graph shows: Hospital admissions for myocarditis, pericarditis and cardiac arrhythmia from April 2019 to October 2021. Myocarditis admissions have been declining throughout 2021 and are not substantially higher than before the start of the vaccine rollout

The study, published in the journal Nature Medicine, looked at data for 38million people vaccinated from December 1 to August 24 this year. Of that, just over eight million were under 30.

Researchers calculated ‘excess’ myocarditis cases — those which would not have occurred without jabs or Covid infection — for each vaccine type. 

Zero cases were found in people aged 16 to 40 who had AstraZeneca — although very few in the age group were given the company’s vaccine. 

Three excess cases per million were found in people who had a second dose of Pfizer’s, while two were seen in those who had first dose from the company. 

Moderna had a slightly higher incidence, rate, with eight cases per million first doses given out and 15 per million second doses. 

Covid itself caused 10 excess cases of myocarditis per million infections — higher than both doses of Pfizer’s and AstraZeneca’s vaccines, but lower than in second doses of Moderna’s vaccine.

Moderna’s vaccine has been approved for use in 12- to 17-year-olds by the MHRA, which gives the final sign off to all drugs used in Britain.

But it is still not recommended by the JCVI, with only Pfizer’s jabs being offered to the age group.

The researchers also showed men were at higher risk, confirming previous research. But it did not break down rates in younger adults. 

Independent experts also believe the risk of myocarditis is lower in younger children than adolescents.

Pfizer's own study suggests unjabbed 12 to 15-year-olds are just three per cent more likely to catch Covid compared to fully vaccinated children earlier this week

Pfizer’s own study suggests unjabbed 12 to 15-year-olds are just three per cent more likely to catch Covid compared to fully vaccinated children earlier this week 

What are the risks of Covid and vaccines to five-year-olds?


Most children only experience mild symptoms after being infected with Covid.

Just one in 300,000 children who test positive for Covid die, according to UK Government data.  

And the risk of being hospitalised and getting admitted to ICU is similarly low.

But the risk is higher to children with serious underlying conditions. 

The JCVI has yet to release its updated guidance on vaccinating children aged 11 and under.

But its latest advice on recommending first jabs to over-12s suggested one Pfizer dose only prevents 131 hospital admissions per million 12-15-year-olds.

And second doses only prevent nine hospital admissions for every million dished out to the age group. 

The figures are likely to be less for five- to eleven-year-old, who are less vulnerable to the virus. 


Myocarditis — an ultrarare form of heart inflammation — is the main side effect of the Pfizer vaccine that concerns experts. 

Data shows the risk is slightly higher in adolescents than adults, particularly in boys.

The JCVI has not released data on how many cases are expected in children aged five to 11 but studies show children in younger age groups are less at risk than teenagers.

It found myocarditis cases in between 2.6 to 17.7 million first vaccine doses in children aged 12 to 15.

And the condition was found in between 20.9 to 42.2 children in the age group per million second doses dished out.

Study co-author Professor Aziz Sheikh, of the University of Edinburgh, said: ‘Overall the message is that these risks are substantially higher in people who develop SARS-CoV-2. 

‘The numbers are very small — but I think overall these data are reassuring for young people as well.’

Professor Nicholas Mills, a consultant cardiologist at the university, added: ‘We’re not seeing any data here that would change the recommendation on vaccinating children.’

They said data on how the Omicron super mutant variant affects myocarditis risk is not yet available. 

Dr Peter English, retired consultant in communicable disease control said: ‘The take-home [is] if you don’t want to get myocarditis or pericarditis, get vaccinated. 

‘If you don’t get vaccinated, with ever more transmissible forms of SARS-CoV-2 virus spreading widely, it is only a matter of time before you get Covid and the risks if you do massively outweigh the risks of vaccination.’

Government advisors are currently in discussion about extending the roll-out to all over-fives by Christmas.

Other countries including the US and all EU member states have already done so.  

Professor Lim told the Science and Technology committee of MPs today: ‘We are discussing that at the moment. 

‘We’re also waiting for the vaccines to be approved by MHRA.’ 

Chairman of the committee Greg Clark asked: ‘So would you expect to make a decision before Christmas on that?’

Professor Lim added: ‘I would expect so, we try and keep in step with the approval process.’ But he did not provide a clearer time-frame. 

Some experts have called for the rollout to be extended to the age group in order to fight off the impending wave of cases and hospitalisation caused by the Omicron strain.

SAGE adviser Professor John Edmunds, an epidemiologist at the London School of Hygiene and Tropical Medicine, called for jabs for five to 11-year-olds ‘as soon as possible’.

Cases have been highest in under-18s since early November, with more than 32,000 recorded per day last week compared to less than 2,000 in over-75s, according to ZOE data published today. 

Speaking at Royal Society of Medicine event, Professor Edmunds said: ‘We’ve, had a large number of cases over the last few months, and unfortunately high numbers of hospitalisations and 100 to 150 deaths a day. 

‘I’m not saying all of that has been driven by children, but much of it unfortunately has.

‘So from taking a population perspective, I think it’s it’s pretty clear we do need to vaccinate our children as well as everybody else.’

Revealed: What are other countries doing about Covid vaccinations for children

The United States starting rolling out Pfizer’s vaccines for children aged 5 to 11 at the start of November.

A panel of outside experts met on November 2 to vote on how broadly the shot should be recommended in the age group by the US Centers for Disease Control and Prevention (CDC). 

The vaccine was authorized by the US Food and Drug Administration in the age group on November 29.

But with many parts of the world still awaiting doses for more vulnerable people, the World Health Organisation has urged countries and companies that control the global supply of the vaccines to prioritize supply to COVAX.

The following is a list of some countries that have approved or are considering vaccinating children:


  • On November 25, the EU’s medicines regulator said it had approved the use of Pfizer and BioNTech’s Covid vaccine in five to 11-year-old children.
  • In June, Denmark said it would offer Covid shots to children aged 12-15 to boost its overall immunity against the virus.
  • France has started vaccinating those from 12 years upwards, provided they have parental consent.
  • Germany in August agreed to make vaccination available to all children aged 12-17.
  • Austria has started vaccinating children aged 12-15.
  • Estonia could start vaccinating teenagers by the autumn, public broadcaster ERR reported, citing the head of the government’s Covid council.
  • Hungary started vaccinating 16 to 18-year-olds in mid-May, according to Xinhua news agency.
  • Italy on May 31 approved extending the use of Pfizer’s vaccine to 12- to 15-year-olds. On July 28, it also endorsed the use of Moderna’s vaccine for 12- to 17-year-old children.
  • Lithuania’s prime minister said the country could start vaccinating children from age 12 in June, news site Delfi reported.
  • Spain begun vaccinating children between 12 and 17 years old around two weeks before the academic year in September, the health minister said.
  • Swedish PM says children aged 12-15 will be offered Covid vaccine later this autumn.
  • Greece in July said children aged 12-15 could be vaccinated against Covid with Pfizer/BioNTech and Moderna shots.
  • Finland’s capital Helsinki in June said it will begin giving Covid vaccines to children aged 12 to 15 who are at risk of contracting a severe coronavirus infection.
  • On July 27, Ireland lowered the age for Covid vaccination to 12 years.
  • Poland started offering Covid vaccines to children of ages 12 to 15.


  • On October 19, UK said it will open up COVID vaccine booking service to those aged 12 to 15.
  • Switzerland approved on June 4 vaccinating 12- to 15-year-olds with Pfizer’s shot, while Moderna’s shot was approved in August for the age group.
  • In September, Norway started to offer one dose of Pfizer and BioNTech Covid vaccine to children aged 12 to 15.


  • In August, Israel began offering a Covid booster to children as young as 12.
  • The United Arab Emirates said in August rolled out China’s Sinopharm vaccine to children aged three to 17. On November 1, UAE approved Pfizer-BioNtech shot for children aged five to 11 for emergency use.
  • Bahrain approved Sinopharm Covid vaccine for children aged three to 11 from October 27, while on November 2, the Gulf state approved the Pfizer vaccine for emergency use for children aged between five and 11 years.


  • Indonesia on November 1 authorised China’s Sinovac vaccine for children aged 6 and above.
  • Malaysia on October 29 said it would procure the Pfizer/BioNTech vaccine for children aged five to 11, following a US expert panel’s recommendation
  • Vietnam will begin inoculating children aged 16 and 17 with parental consent from next month using the Pfizer-BioNTech vaccine.
  • An advisory committee to the Indian regulator recommended emergency use of Bharat Biotech’s Covid shot in the two to 18 age group. The regulator’s nod is awaited.
  • New Zealand’s medicines regulator in June provisionally approved use of Pfizer’s vaccine for 12- to 15-year-olds.
  • Australia said on September 12 it will expand its COVID-19 vaccination drive to include around one million children aged 12 to 15.
  • China on June 5 approved emergency use of Sinovac’s vaccine for those between three and 17.
  • Hong Kong said on June 3 it would open its vaccine scheme to children over the age of 12.
  • Singapore opened up its vaccination programme to adolescents aged 12 to 18 from June 1.
  • Japan on May 28 approved the use of Pfizer’s vaccine for those aged 12 and above.
  • The Philippines on May 26 decided to allow the Pfizer-BioNTech’s vaccine for emergency use in children aged 12 to 15.
  • Jordan in July begun vaccinating children aged 12 years and older against Covid.


  • The Covid vaccine by Pfizer-BioNTech will be the only one used in Mexico for at-risk children aged 12 to 17.
  • Brazil on June 11 approved use of Pfizer’s vaccine for children over 12.
  • On September 6, Chile approved the Covid vaccine produced by China’s Sinovac Biotech Ltd for use in children over 6 years of age.
  • US FDA has authorized the Pfizer vaccine for children aged five to 11 years. CDC Director Rochelle Walensky must make her recommendations before it can be rolled out.
  • Canada in early May approved use of Pfizer’s vaccine for use in children aged 12 to 15 but the decision for children between 5 an 11 years is not likely to come before mid- to end-November.
  • Cuba’s vaccination campaign includes children as young as two.
  • On September 13, El Salvador cleared the use of COVID-19 vaccine in 6 to 11-year-old children. 
  • Argentina is vaccinating children as young as three with Sinopharm COVID-19 vaccine. 
  • Ecuador’s vaccination includes kids as young as six with the China’s Sinovac vaccine
  • Columbia is offering Pfizer, AstraZenenca, Moderna, Sinopharm and J&J’s Covid vaccines for children 12 years and above.
  • Costa Rica is vaccinating 12 years and above.


  • South Africa will start vaccinating children between the ages of 12 and 17 next week using the Pfizer vaccine.

Reporting by Reuters