2 US Coronavirus Vaccines May Be Linked to Rare Heart Condition, CDC Says  

The U.S. Centers for Disease Control and Prevention said Wednesday there is a likely association between two COVID-19 vaccines and a rare heart condition in boys and young men. 

The federal health agency said more than 1,200 people who had received either the PfizerBioNTech or Moderna vaccines developed myocarditis, or inflammation of the heart muscle. The condition was more prominent in men than women, and was detected more after the second dose than the first.    The CDC said the side effects, which include fatigue and chest pain, have been mild and that the vast majority of those diagnosed with myocarditis have fully recovered.  The agency concluded that despite the “likely association” between the two vaccines and myocarditis, the benefits of receiving the vaccine far outweigh the risks.    Both the Pfizer and Moderna two-shot vaccines were developed using messenger RNA, which is a single-stranded RNA molecule that is complementary to one of the DNA strands of a gene, according to the National Human Genome Research Institute.