"This landmark study published in The Lancet Child & Adolescent Health provides the clearest and most comprehensive evidence to date that COVID-19 infection poses a far greater and longer-lasting risk of rare cardiovascular and inflammatory complications in children than vaccination. Using anonymised, linked electronic health records covering almost 14 million children and young people under 18 years of age in England, researchers analysed outcomes following both first SARS-CoV-2 infection and first Pfizer-BioNTech (BNT162b2) vaccination. This large-scale, population-based analysis drawing from 98% of all general practices and linked hospital, emergency, testing, dispensing, and death registry data represents one of the most complete paediatric datasets assembled anywhere in the world.

The study followed children diagnosed with COVID-19 between January 2020 and March 2022 and compared them with vaccine-eligible children aged 5 to 17 years who received their first Pfizer-BioNTech dose between August 2021 and December 2022. Researchers looked for rare but serious conditions including arterial and venous blood clots (thromboses), thrombocytopenia (low platelet count), myocarditis and pericarditis (heart inflammation), and systemic inflammatory syndromes such as PIMS/MIS-C. Sophisticated time-based statistical models were used to compare risk before and after infection or vaccination, while adjusting for factors such as age, sex, ethnicity, region, socioeconomic deprivation, and healthcare use.

The results were striking and consistent across all outcomes. In the first week after a COVID-19 diagnosis, children experienced a significant spike in risk for several complications: arterial clots were 2.3 times more likely, venous clots 4.9 times, thrombocytopenia 3.6 times, myocarditis or pericarditis 3.5 times, and systemic inflammatory conditions nearly 15 times higher than baseline. Importantly, many of these risks did not disappear quickly. In fact, elevated risks for blood clots, low platelets, and heart inflammation persisted for up to 12 months after infection, indicating potential long-term consequences of SARS-CoV-2 infection even in young populations previously thought to be at minimal risk.

In contrast, the vaccine safety profile was far more favourable. After the first dose of Pfizer-BioNTech vaccine, there was a small and short-lived increase in myocarditis and pericarditis risk within the first four weeks (hazard ratio 1.84), but no evidence of ongoing or long-term elevated risks thereafter. There were no consistent increases for blood clots, platelet disorders, or inflammatory syndromes. In fact, the study found vaccination was associated with lower rates of systemic inflammatory conditions compared with unvaccinated children, highlighting a possible protective effect.

When researchers compared absolute excess risks over six months, the number of additional cases per 100,000 children, they found the differences were clear and easily interpretable. After infection, there were approximately 2.24 additional cases of myocarditis or pericarditis per 100,000 children; after vaccination, only 0.85 per 100,000. This translates to roughly 2 to 3 additional heart inflammation cases per million children after infection compared with around one per million following vaccination. In other words, the risk of heart inflammation after infection is roughly two to three times higher than after vaccination, and vaccine-related cases tend to be milder and resolve faster.

These findings have major implications for parents, clinicians, and policymakers. For parents and caregivers, the data provide reassurance that vaccination is not only safe but also substantially safer than infection itself in terms of rare cardiac and vascular complications. For clinicians, it underscores the need for vigilant follow-up of children recovering from COVID-19, particularly for delayed or persistent complications such as myocarditis, blood clots, and inflammatory syndromes. For policymakers and public health leaders, this study offers compelling evidence to support ongoing paediatric vaccination campaigns and clear communication strategies that focus on comparative risk, using straightforward numbers that families can easily understand.

Beyond the scientific findings, the message is simple and powerful! While both infection and vaccination can rarely trigger heart inflammation, the risks following infection are higher, last longer, and often affect multiple organs. Vaccination, on the other hand, carries a much smaller and short-lived risk that resolves within weeks. The study’s scale, methodological rigour, and long follow-up provide high confidence in these conclusions.

In summary, infection-related complications in children, though rare, are more frequent, more severe, and more prolonged than those linked to vaccines. Vaccination remains the safer and more protective path, shielding children not only from these complications but also from the wider consequences of severe COVID-19 and long COVID. The overall takeaway is clear: for children and young people, the benefits of vaccination far outweigh the risks and it remains one of the most effective measures to protect their hearts, their health, and their futures!"

“While authorities have difficult, all-things-considered, recommendations to make, the case for vaccinating otherwise healthy children against the acute and chronic impacts of COVID-19 has been strong for a while. This important work further strengthens the case.”

"This study in The Lancet Child & Adolescent Health, has very clearly demonstrated by studying 14 million children that the risk of heart inflammation, myocarditis or pericarditis is higher after COVID-19 infection than it is after receiving a COVID-19 vaccination. The risk is still there after vaccination, but it is around half of the risk faced due to acute infection with the disease itself. 

We know that repeated infection with COVID-19 is common for children, and this study has added to the evidence that these acute infections are putting their health at risk, this study shows that vaccination substantially decreases this risk, even in those who get a mild infection. That’s an important reassurance for parents weighing up the benefits and risks.

As our understanding evolves, vaccination policy will too. This study underscores that vaccines continue to play a valuable role in protecting young people from the damaging effects of COVID-19 infection. It’s essential we communicate that nuance clearly: the science isn’t static — it’s improving — and with that, our ability to make informed, balanced decisions for children’s health improves as well.”

"This study provides important evidence showing that the risk of inflammatory heart conditions in children is actually higher after COVID-19 disease than it is after vaccination against COVID-19. This is very important information that will significantly aid decision-making surrounding vaccination of children against COVID-19.

The study does not comment on any link between COVID-19 vaccination and disease prevention in children (nor does it claim to do so) and, as such, efficacy studies are also required to provide a fuller picture of childhood COVID-19 vaccination."

"This high-quality study provides further evidence for what is already known to be the case regarding the vascular and inflammatory risks of both COVID-19 and COVID-19 vaccines. Many studies have demonstrated that while both carry risks, these risks are generally greater from COVID-19 infection than from the COVID-19 vaccines and this was also the conclusion of this study. While it was retrospective, this was a very large study that looked at the records of nearly 14 million children less than 18 years of age and captured nearly four million COVID-19 diagnoses.

Following a diagnosis of COVID-19, there was a higher risk of many vascular and inflammatory conditions, including arterial thromboembolism, venous thromboembolism, thrombocytopenia and myocarditis or pericarditis. This risk was highest in the first week and remained elevated even out to beyond 12 months for venous thromboembolism, thrombocytopenia and myocarditis or pericarditis.

There were risks associated with COVID-19 vaccination reported also, including an elevated risk of myocarditis or pericarditis within the first four weeks after vaccination. However, perhaps most importantly, the risk following vaccination was substantially lower than the risk following infection.

COVID-19 vaccine recommendations for children remain controversial, due to many different and conflicting positions regarding the need to vaccinate particularly children with no associated risk factors. While more severe disease from COVID-19 infection is known to be more associated with advanced age and comorbidities, this study provides further evidence both of the significant complications of COVID-19 infection in children and the relative safety of the vaccines that therefore could, or perhaps should, be more widely recommended to reduce these risks."

"This study confirms what many other studies have shown - that COVID-19 mRNA vaccines are safe and effective in reducing the risks of serious complications of COVID infection. No vaccine or drug is 100% safe. As all have side effects, but they go through a rigorous process to ensure that the benefits far outweigh the risks. This study and other studies show the risk benefit clearly favours vaccines for children.  The risk of myocarditis is low - 1-3 per 100,000 children. There is a much higher risk of myocarditis after COVID infection, as we have also shown. (https://pubmed.ncbi.nlm.nih.gov/36937372/)

The COVID mRNA vaccines are actually protective of the heart, because of the enormous damage the infection can cause to the heart. (https://pubmed.ncbi.nlm.nih.gov/39656843/.) One study (see our first cited paper)  even showed a rise in cardiac troponin, a marker of heart injury, in infants with COVID infection. That we deny vaccination to children is inexplicable.

Until a few months ago, the US used to publish age specific death rates from COVID-19, and showed the COVID is the leading infectious cause of death in children. It has surpassed influenza in this dubious honour. Many vaccine preventable diseases, including polio, have serious complications or death in only a small percentage of children, but when we live with mass infection, that translates to a lot of serious illness and death in kids. Yet we hear classic anti-vaxxer arguments that inflate the risks of vaccines and minimise the disease, even among medical professionals, as I write about in my book, Vaccine Nation.

Our children are not eligible for vaccination at all, and vaccination is not even recommended wholeheartedly even for young adults. Long COVID is another crippling impact on everyone, especially kids and working age adults. We showed that young working adults bear the largest burden of Long COVID. (https://pubmed.ncbi.nlm.nih.gov/39154292/) Rolling Stone ran a feature article about the impact of Long COVID on children recently. I hope this study will inform vaccine policy for children."

"This is an interesting paper which presents data supporting higher rates of the heart conditions myo and peri-carditis in children 5-18 years following COVID-19 infection than following vaccination. This is a little surprising as certainly in the Australian context I am not aware of similar findings. There is also another well-designed paper, also using UK data, just out now in Epidemiology (DOI: 10.1097/EDE.0000000000001908) that comes to basically the opposite conclusion.

This situation is great for controversy but not for consensus - which is correct? I think the difference may come down to which time periods are looked at for COVID infections. In the Lancet study they look at infections that occurred between January 2020 and March 2022 but compare this to vaccinations that occurred between August 2021 and December 2022, whereas in the Epidemiology study the same start date and follow-up period were chosen for both infections and vaccination (also August 2021). Earlier COVID variants tended to be associated with more severe disease consequences and I wonder if that might explain the difference.

A sensitivity analysis looking at the effect of time period would have been a useful addition to the Lancet study. I also would have liked to see their absolute excess risk estimates broken down by age and sex as other evidence would suggest important differences between younger children and adolescents, as well as sex in risks from covid infection and vaccine adverse events. In summary, this is useful data but the main conclusion of the press release is not as clear-cut as the authors contend."