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.
An official with the U.S. Food and Drug Administration said after the results were announced that the regulatory agency would add a warning for health care providers and vaccine recipients about the potential risk of the side effect.
US sends vaccines to Brazil
In other news, the White House is sending 3 million doses of the single-shot Johnson & Johnson COVID-19 vaccine to Brazil on Thursday. The shipment, which will arrive in the city of Campinas, near Sao Paulo, is part of U.S. President Joe Biden’s pledge to donate 80 million doses to other countries by the end of the month.
A White House official said “scientific teams and legal and regulatory authorities” from both nations collaborated to secure the arrangement.
Brazil has posted 507,109 COVID-19 deaths, second only behind the United States, which has 602,837, according to Johns Hopkins Coronavirus Resource Center.