https://edition.cnn.com/2021/06/09/health/myocarditis-covid-vaccination-link-clearer/index.html

A link between Covid-19 vaccination and a cardiac illness may be getting clearer

Vaccine advisers to the US Centers for Disease Control and Prevention say there has been a higher-than-expected number of cases of a heart ailment among young people, most often males, who've recently received their second doses of the Pfizer and Moderna Covid-19 vaccines. The CDC says the reports of the ailment are "rare" and that "most patients who received care responded well to medicine and rest and quickly felt better."

The advisers' statement, posted June 1 on the CDC website, strikes a different note from their statement about two weeks earlier, which said that the rates of myocarditis -- inflammation of the heart muscle -- were not higher among vaccinated people than among unvaccinated people. 

The new report comes as the Israeli Ministry of Health finds a "likelihood of a link" between the second dose of the Covid-19 vaccine and myocarditis, most commonly among males ages 16 to 30.

The June 1 report by a work group of the CDC's Advisory Committee on Immunization Practices states that within 30 days of receiving the second dose of either Pfizer or Moderna vaccines, "there was a higher number of observed than expected myocarditis/pericarditis cases in 16-24-year-olds."

This outside group of experts, many of them physicians at academic medical centers, advises the CDC, but doesn't represent the agency itself. The CDC has not said if the number of cases of the heart ailments is higher than expected.

The CDC says on its website that benefits of Covid-19 vaccination outweigh the known and potential risks "including the risk of myocarditis or pericarditis," which is swelling of the tissue around the heart. The agency says it is "actively monitoring these reports, by reviewing data and medical records, to learn more about what happened and to see if there is any relationship to COVID-19 vaccination."

The cases occurred mostly among male adolescents and young adults age 16 years or older, typically within several days after vaccination and more often after getting the second shot than after the first, according to the CDC.

The agency advises people to be on the lookout for certain symptoms following Covid-19 vaccination, such as chest pain, shortness of breath and heart palpitations.

The CDC has reached out directly to state health departments and medical societies, such as the American Academy of Pediatrics and other groups about the myocarditis reports. The agency has also issued several statements on its website in the past few weeks about myocarditis following the two mRNA vaccines, Pfizer and Moderna, including one for physicians and one for the public.

Aside from these pages, CDC officials have not directly communicated to the public about any possible risk of myocarditis with the vaccines. CDC declined CNN's request to speak with an expert, instead issuing a statement by a spokesman.

The increase in myocarditis cases could be, at least in part, because the CDC and the American Academy of Pediatricians prompted doctors to be watchful for such cases.
But a source familiar with the situation told CNN it's appearing more and more likely that there is a real link between the vaccine and the cases.
"It looks like this is a biological phenomenon rather than a chance event," the source said. "It looks to be a pattern and not just random."
"They're not sure yet whether there is a causal association, but they're keeping a close eye on this," the source said. "They're open to the notion that this may be a causal situation, but the case is not conclusive yet, and it's certainly not enough to change their recommendations -- they will continue to recommend very clearly that everyone over age 12