DoubleChecks

What was claimed

Myocarditis and pericarditis only appeared in children who received the COVID mRNA vaccine (1.7 million children study); zero cases in unvaccinated kids - they lied saying it was extremely rare

Our verdict

Inaccurate

Large population-based studies in children and young people show myocarditis and pericarditis occur both after mRNA vaccination and after COVID-19 infection, with higher and longer-lasting risk after infection than after vaccination. These studies explicitly report elevated risk in unvaccinated children following infection, so the conditions do not appear only in vaccinated children. Unvaccinated children who contracted COVID-19 developed myocarditis and pericarditis. Studies show higher rates in unvaccinated infected children than in vaccinated children. One study found myocarditis risk 11 times higher in unvaccinated individuals after COVID-19 infection.

All 3 AI systems agree10 sources citedChecked Jul 12, 2026

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Key findings

They lied saying it was extremely rare

Incorrect93%
All 2 AIs agree

Myocarditis and pericarditis only appeared in children who received the COVID mRNA vaccine (1.7 million children study); zero cases in unvaccinated kids

Incorrect95%
4 of 5 AIs agree·Perplexity: Can’t verify

Zero cases in unvaccinated kids

Incorrect99%
1 AI checked

1.7 million children study

Can’t verify60%
1 AI checked

Verified against 10 sources

pubmed.ncbi.nlm.nih.govbmj.comsciencemediacentre.orgpmc.ncbi.nlm.nih.govjacc.orgchoa.orgcdc.govmed.stanford.edugosh.nhs.uksciencedirect.com

Detailed Analysis

The response incorrectly claims myocarditis and pericarditis only occurred in vaccinated children and not in unvaccinated children, which is contradicted by large, high-quality studies. It also wrongly asserts there were zero cases in unvaccinated kids and that authorities lied about the events being extremely rare, both of which are inconsistent with current evidence. The overall message is factually wrong and misleading about relative and absolute risk.

Why this verdict

  • The response incorrectly claims myocarditis and pericarditis only occurred in vaccinated children and not in unvaccinated children, which is contradicted by large, high-quality studies.
  • It also wrongly asserts there were zero cases in unvaccinated kids and that authorities lied about the events being extremely rare, both of which are inconsistent with current evidence.
  • The overall message is factually wrong and misleading about relative and absolute risk.

Claims checked

They lied saying it was extremely rare

Incorrect90%
Multiple studies and official summaries state that myocarditis/pericarditis after mRNA COVID-19 vaccination is a real but rare adverse event, with absolute risks on the order of tens of cases per million doses or less than 0.01%.[4] [6] [7] [8] [10] Describing these events as very rare is consistent with the observed rates, so calling such statements lies is not supported by the evidence.

This claim may mislead readers without added context.

Myocarditis and pericarditis only appeared in children who received the COVID mRNA vaccine (1.7 million children study)

Incorrect95%
Large population-based studies in children and young people show myocarditis and pericarditis occur both after mRNA vaccination and after COVID-19 infection, with higher and longer-lasting risk after infection than after vaccination.[2] [3] [9] These studies explicitly report elevated risk in unvaccinated children following infection, so the conditions do not appear only in vaccinated children.[2] [9]

This claim may mislead readers without added context.

Zero cases in unvaccinated kids

Incorrect95%
Research in England using linked health records for about 85% of children found extra cases of myocarditis or pericarditis following COVID-19 infection in children and young people, who by definition are not protected by vaccination at the time of infection.[2] [9] The study estimates 2.24 additional cases per 100,000 children after infection, which contradicts the claim of zero cases in unvaccinated kids.[2] [9]

This claim may mislead readers without added context.

What other AI think

The claim makes several demonstrably false assertions. Myocarditis and pericarditis have been documented in unvaccinated children with COVID-19 infection, and multiple large studies show higher rates in unvaccinated infected individuals than in vaccinated ones. The characterization as "extremely rare" is accurate, not a lie. The referenced 1.7 million study appears to misrepresent findings.

Why this verdict

  • The claim makes several demonstrably false assertions.
  • Myocarditis and pericarditis have been documented in unvaccinated children with COVID-19 infection, and multiple large studies show higher rates in unvaccinated infected individuals than in vaccinated ones.
  • The characterization as "extremely rare" is accurate, not a lie.
  • The referenced 1.7 million study appears to misrepresent findings.

Claims checked

They lied saying it was extremely rare

Incorrect95%
The characterization of vaccine-associated myocarditis as 'extremely rare' is accurate. Studies document rates of approximately 5-6 cases per million doses, or 0.00063% incidence. This is factually rare, not a lie.

This claim may mislead readers without added context.

Myocarditis and pericarditis only appeared in children who received the COVID mRNA vaccine

Incorrect98%
Multiple studies document myocarditis and pericarditis in unvaccinated children with COVID-19 infection. A Spanish hospital study found incidence of 10/100,000 in vaccinated adolescents vs. 20/100,000 in unvaccinated adolescents. A UK study of 13.9 million children found COVID-19 infection led to 2.24 extra cases per 100,000 children vs. 0.85 after vaccination.

This claim may mislead readers without added context.

Zero cases in unvaccinated kids

Incorrect99%
Unvaccinated children who contracted COVID-19 developed myocarditis and pericarditis. Studies show higher rates in unvaccinated infected children than in vaccinated children. One study found myocarditis risk 11 times higher in unvaccinated individuals after COVID-19 infection.

This claim may mislead readers without added context.

The statement is factually incorrect and misleading. High-quality studies and surveillance show myocarditis/pericarditis can occur after both mRNA vaccination and SARS‑CoV‑2 infection, and they have been observed in unvaccinated children in some datasets.

Why this verdict

  • The statement is factually incorrect and misleading.
  • High-quality studies and surveillance show myocarditis/pericarditis can occur after both mRNA vaccination and SARS‑CoV‑2 infection, and they have been observed in unvaccinated children in some datasets.

Claims checked

Myocarditis and pericarditis only appeared in children who received the COVID mRNA vaccine (1.7 million children study); zero cases in unvaccinated kids

Incorrect90%
While at least one large dataset (e.g., an OpenSAFELY analysis) reported myocarditis/pericarditis events documented in vaccinated groups within their study window, multiple other population studies and surveillance systems report myocarditis/pericarditis after SARS‑CoV‑2 infection and have documented cases among unvaccinated children; therefore the absolute claim of "only" and "zero cases" among unvaccinated children is incorrect and overgeneralized.

This claim may mislead readers without added context.

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