A study of 301 teens in Thailand found mild and temporary heart rhythm changes after a second dose of the Pfizer-BioNTech COVID-19 vaccine among one in six teenagers, not one-third as social media posts claim. The study also saw possible signs of heart inflammation in just seven of those teens with rhythm changes and confirmed myocarditis in only one of the seven. Social media users are circulating the study of post-vaccination heart effects in Thai teenagers with the claim that a third of participants experienced heart effects, and the suggestion that the results indicate a new danger level for children....