The study, which British researchers released in late December, showed that the risk of myocarditis almost doubled after the first Pfizer shot in men under 40. Then it doubled again after the second and doubled again after the third - to almost eight times the baseline risk.

https://alexberenson.substack.com/p/more-bad-news-on-covid-vaccines-and/comments

https://www.medrxiv.org/content/10.1101/2021.12.23.21268276v1.full.pdf