Doubts over study linking mRNA vaccines and adolescents’ myocarditis risk

Anastasia Tsirtsakis

14/09/2021 5:01:52 PM

A study co-author has been connected to an online group opposing pandemic public health measures, from mask-wearing and lockdowns to mandatory vaccinations. 

Young boy receiving Pfizer vaccine.
The TGA has recorded 12 cases of suspected myocarditis/pericarditis in children aged aged 15–17. (Image: AAP)

The pre-print study, uploaded to the medRxiv server on 8 September, suggests boys aged 12–17 without medical comorbidities are more likely to develop a cardiac adverse event (CAE) that requires hospitalisation following vaccination with either Pfizer or Moderna than they are to be hospitalised with COVID-19.
The research, led by Dr Tracy Høeg from the University of California, used the Vaccine Adverse Event Reporting System (VAERS) to identify 257 CAEs among vaccinated adolescents between 1 January and 18 June. 
It found rates of CAE were 16.2 per 100,000 for 12–15-year-old boys and 9.4 per 100,000 for 16–17-year-olds. The rates for girls were significantly lower, at 1.3 per 100,000 and 1.34 per 100,000, respectively.
The authors concluded that the rate of CAE for healthy boys aged 12–15 is 3.7–6.1 times higher than their risk of being hospitalised for COVID-19, and 2.1–3.5 times higher for boys aged 16–17.

However, doubt has been cast over the study as news has emerged that a co-author, Josh Stevenson, is associated with Rational Ground, an online group that has opposed public health measures, including mandatory vaccinations, throughout the pandemic. 
Questions have also been raised over the study’s use of data from the VAERS platform, which relies on unverified self-reports of side effects that have reportedly been used by the anti-vaccination movement to spread misinformation.
This revelation has given way to concerns that the study could be causing unnecessary anxiety among parents and carers, as Australia and the UK have now included 12–15-year-olds in their COVID vaccination programs.   

Professor Robert Booy, an infectious diseases paediatrician and vaccine expert, urged caution in interpreting the study. While there is considerable evidence that myocarditis is a real, albeit rare, side effect of the mRNA vaccines, he said the true risk estimate is likely to be more conservative.
‘The truth of the data probably rests more at a risk of between one in 15,000–20,000 [5–6.66 per 100,000],’ Professor Booy told newsGP. ‘And, fortunately, it is rarely leading to serious consequences or long-term damage.
‘It’s extremely unlikely for a CAE to last longer than 1–2 weeks and a fatal outcome is extremely rare – I think I’ve read one case report.’
It was in July that the Therapeutic Goods Administration (TGA) included a warning statement about myocarditis and pericarditis as rare sides effect of Pfizer, particularly among males under 30.
In its latest safety report, the regulator said that up to 5 September it had received 370 reports of suspected myocarditis and/or pericarditis following vaccination with Pfizer, including 10 boys and two girls aged 15–17. Five cases occurred after the first dose and seven after the second dose.
The rare side effects typically occur within 10 days of vaccination, particularly after the second dose, and more often in younger men.
However, the TGA notes that ‘myocarditis and pericarditis are much more common with COVID-19 infection and damage to the heart is frequently severe after infection’.
Professor Booy assures that the Australian regulator, along with those in the UK and US, are continually and carefully looking at emerging data, and that the risk–benefit analysis to date remains in favour of vaccination.
While the emergence of the Delta strain has resulted in COVID-19 spreading more easily in schools, recent Australian research found that most children have only mild disease. And though child deaths from COVID remain rare, with none recorded in Australia to date, Professor Booy says they do – and have – occurred overseas.
‘In the United States, they have 400 children under the age of 18 who’ve died and probably half had a predisposed condition,’ he said.
‘That means half would have been healthy and could only benefit by universal vaccination.’
But Professor Booy said the benefits of vaccination are far-reaching.
‘You’re much better off being vaccinated as a teenager than getting COVID disease, even though it’s relatively mild,’ he said.
‘The added advantage of being able to go back to school, social economic improvements and confidence that people have around COVID prevention and protection lean to multiple reasons for having a preference for vaccinating teenagers.’
With the majority of myocarditis cases occurring after the second dose, the UK has decided to offer 12–15-year-olds a single dose of either Pfizer or Moderna.
Professor Booy said further investigation is needed to confirm whether reducing the dosage protocol would offer enough protection – and whether it would even reduce the likelihood of myocarditis.
‘Protection against COVID by one dose of vaccination in teenagers is very high, and it would be very worthwhile to do good surveillance in Australia to better understand whether one dose is enough,’ he said.
‘We don’t know whether a lower dose will reduce the likelihood of myocarditis, but it’s a good question.’
Professor Booy did urge caution in paying too much attention to pre-print studies, and said the peer-review process is in place for good reason.
‘It’s an important thing to pay attention to; it is relevant,’ he said. ‘But the harm–benefit still favours vaccination, particularly for a side effect that is only mild to moderate.
‘Parents worried about their athletic teenagers having the vaccine would be wise to keep them away from strenuous exercise for five days after vaccination.
‘But the TGA, the CDC [Centers for Disease Control and Prevention] and MHRA [Medicines and Healthcare products Regulatory Agency] have all looked at it, and they’ve reassured themselves that it’s safe.’
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Getafx   15/09/2021 6:41:21 AM

Why does being in online group disqualify a scientific study ? Did he join the group after the results of study ?

Dr Matthew Hugh Routley   15/09/2021 10:52:04 AM

Hi Anastasia. Thanks for your article on myocarditis and mRNA vaccines. Could I make several comments?
1. the VAERS database for reporting adverse events from COVID19 vaccines is voluntary. Voluntary databases under-report the true incidence of an adverse event by up to 90-99%. Therefore, the true incidence of myocarditis in young adults in this study is likely significantly higher than that reported, not lower as suggested by Prof. Rooy
2. Secondly, myocarditis is not benign. It is catastrophic for those who get it. "Recovering" from myocarditis means you don't die from it, but most people's health never is the same. Up to 45% of all heart transplants in the US are believed to be due to myocarditis-related cardiomyopathy.
3. Thirdly, healthy, young adults under the age of 50 are at almost zero risk of getting seriously sick or dying from COVID. Exposing them to ANY life-threatening risk from a new vaccine is unacceptable

Dr Matthew Hugh Routley   15/09/2021 10:55:14 AM

4. Despite an authors conflict of interest, the data should be looked at and assessed on its merit- data doesn't lie, but its interpretation can be twisted by anyone.

Dr Kenneth Albert Landers   15/09/2021 12:53:46 PM

I want to respond to some comments by Dr Routley as I think he has missed some important points VAERS may be underreported but in this instance may be over-reported as the anti-vaxxers a using all avenues to mislead people. secondly it's true that data does not lie but a self-reported unverified/ unverifiable account does not constitute data in my opinion.

Dr Kenneth Albert Landers   15/09/2021 1:01:10 PM

Sorry forgot one thing, under point 3 the recent spate of deaths in Sydney of Under 50's are a warning about being complacent that if you're under 50 and healthy U R OK

Dr David Maxwell Gillis   15/09/2021 9:40:34 PM

responding further to Dr Routleys comments. re Point 3. It is NOT almost zero. Worldwide data suggests there is a significant morbidity and mortality rate for under 50s from COVID19. cited by multiple statistical sites at 2-5 deaths per 1000 cases which is not insignificant ( plus 10 % hospital admission, long covid etc etc). Furthermore in response to point 2- If you are concerned about the impact of myocarditis You would therefore need to be an advocate for the vaccine as "myocarditis and pericarditis are much more common with COVID-19 infection and damage to the heart is frequently severe after infection". I agree with Dr Landers wholeheartedly

Dr Matthew Hugh Routley   18/09/2021 9:40:22 AM

Dear Dr Gillis and Landers.
Can you please provide me with non-media based data that demonstrates that healthy (without accepted risk factors for Covid) young people are succombing to Covid in Sydney? I will happily look at it.
However, its disingenuous to suggest that people who self report adverse events are "anti-vaxxers". "Anti-vaxxers" wouldn't get vaccinated therefore would have nothing to report. While a report to VAERs doesnt imply causation with the vaccine, the number of reported adverse events and deaths to ALL international databases (TGA DAEN, VAERS, UK Yellow Card etc) following introduction of the Covid vaccines are orders of magnitude greater than the reported adverse event baseline for the previous decades. Something is amiss, and as doctors we should be demanding answers to this. It cant simply be "anti-vaxxers".
Im not "anti-vax", but when I see a spike in adverse events it is my responsbility as a doctor to ask why?

Dr Anna Luule Aisatullin   17/10/2021 6:51:54 PM

Can there be further discussion why the UK has adopted the one dose approach in 12-15 years old who do not have other risk factors? This will reduce the risk of myocarditis and they will consider 2nd dose when there is more data