Worried about how your heart might react to a coronavirus vaccine? Well, Fox News host Tucker Carlson sure is.

“As of tonight, the VAERS database reports more than a thousand cases of heart inflammation in people 30 and under who have taken the vaccine,” said Carlson on his Monday night program, referring to the Vaccine Adverse Event Reporting System, which is co-managed by the Centers for Disease Control and Prevention and the Food and Drug Administration to evaluate possible vaccine side effects. “Is that a big deal? Is it not? Should we worry about that? How are those people doing? We don’t know.”

Contrary to Carlson’s claim, we have a great deal of information about the condition of vaccinated people who developed symptoms of myocarditis — essentially heart-muscle inflammation. In early July, the CDC issued an update regarding instances of myocarditis following the use of the mRNA vaccines (i.e., Pfizer-BioNTech and Moderna vaccines). An “elevated risk” of myocarditis was observed, reports the CDC, among those who’ve taken mRNA coronavirus vaccines, with the cases most common among young males. And according to the update, many of “those people” resolved their symptoms with “conservative treatment, such as receipt of nonsteroidal anti-inflammatory drugs.” (Slide 22 in this CDC presentation includes a breakdown of outcomes.)

Media organizations, including Fox News, have picked up on a case here and there. Alex Berenson, the former New York Times reporter who appears regularly on Carlson’s show, has packed his Twitter feed with myocarditis anecdotes skewering official claims that the cases have been “mild.” And: “There is no such thing as mild symptomatic myocarditis that puts a young person in the hospital,” a cardiologist told Wired magazine — and the CDC found that of the 323 people meeting the agency’s “case definitions,” 309 were hospitalized.

More: An Israeli study found, “In most cases myocarditis took the form of mild illness that passed within a few days.” A U.S. study of seven patients reported that all had recovered with hospital stays from two to six days. A study of 23 members of the U.S. military indicated that “all patients received brief supportive care and were recovered or recovering at the time of this report.”

The claim about the unknown fate of myocarditis patients was only half of Carlson’s Monday night offensive, which also included these allegations: “As of this week, the CDC and the FDA say it confirmed more than 600 reports of heart inflammation and swelling and that number is almost certain to rise,” said Carlson. “What’s the context for those numbers? Is that a full count? Is it an undercount? Why isn’t anyone trying to find out? And why aren’t they telling us?” Notice the contradiction: If no one’s trying to “find out,” then how is it that the CDC and the FDA have a confirmed count?

A detailed July 6 CDC document explains how the organization arrived at its guidance that the benefits of vaccination outweigh the risks, including the possibility of myocarditis. It outlines meeting after meeting to plow through the data and the trade-offs involved in pitting vaccine risks versus covid risks. For males age 12-24, the myocarditis risk after the second dose of an mRNA vaccine is 1 in 15,000-20,000.

In any case, the FDA on June 25 announced changes to the patient and provider fact sheets to include warnings about the “suggested increased risks of myocarditis (inflammation of the heart muscle) and pericarditis (inflammation of the tissue surrounding the heart) following vaccination.” That move received ample coverage in the media.

Next up is Carlson’s sneering demand to know whether the numbers represent a full count or an undercount. Any public-health effort that reaches more than 160 million people is, by its very nature, messy and sprawling. The FDA, CDC and the pharmaceutical companies must evaluate the reports that stream into VAERS and sort out the implications. VAERS is a passive system, meaning that it merely receives reports from patients, health-care providers and pharmaceutical companies. Not all patients who may have experienced myocarditis post-vaccination will report their condition, a factor that could mean it undercounts the numbers; then again, the symptoms in some patients may not have been caused by the vaccine, a factor that could mean it overcounts the numbers.

Given these real-world constraints, in other words, the certainty demanded by Carlson is all but unattainable. “By its nature, the data we have are an incomplete picture of everything that’s going on, but it may be the best that we can do,” says Peter Lurie, president of the Center for Science in the Public Interest and a former FDA associate commissioner (and a friend of the Erik Wemple Blog Family). “To my mind, the agencies have been sharing that information in a forthcoming and rapid way.”

Myocarditis is becoming a frequent thematic symptom of “Tucker Carlson Tonight.” Last month, he discussed Israel’s experience vaccinating people 16 years and older since January. In April, the country’s health officials reported more than 60 cases of myocarditis, concentrated in young men. The Israeli health ministry in early June announced the results of a study finding “some probability for a possible link between the second vaccine dose and the onset of myocarditis among young men aged 16 to 30.” Ninety-five percent of the cases are “considered to be mild.”

When Carlson discussed the study, though, he highlighted another finding, “Researchers determined that the incidence of myocarditis in vaccinated young men was fully 25 times the usual rate. Some of them died.”

That formulation might just scare viewers of “Tucker Carlson Tonight,” who could conclude that dozens or hundreds of young Israeli men had succumbed as a result of their vaccinations. But an Israel news outlet reported that there were just two myocarditis deaths in connection with the vaccines. However, when the Erik Wemple Blog asked the Israeli health ministry about the deaths, we received this response: “Cases of fatal myocarditis do occur in the general population with no link to the vaccine. Among young people we have seen one fatal case of myocarditis after vaccination but it has not been definitively linked to the vaccine.”

More from the Israeli health ministry: “In most cases, myocarditis took the form of mild illness that passed within a few days.”

On his Wednesday night program, Carlson continued to promote himself as among the few voices not "following along” with the media establishment’s effort to suppress the truth about vaccines. “Everyone else is. At CNN, they are worried about reports of vaccine-related injuries. They are worried you’ll hear about them, so they spend most of their time daydreaming about ways to punish people who refuse to take the vaccine.” If that were true, then CNN wouldn’t have spotlighted the myocarditis worries in articles published June 9, June 17, June 23, and June 25. One of those stories noted that the CDC had essentially flip-flopped on its assessment of myocarditis and the vaccines, following a statement in May that myocarditis rates didn’t differ from “expected baseline rates.” “It’s not clear what changed by June 1, when the CDC advisers reported that myocarditis cases following vaccination in the 16-to-24 age group were higher than expected,” reads the CNN story.

What a reckoning Carlson would face if only his viewers deployed their search engines.

Fox News these days is making a lot of news with its vaccine split-personality disorder. While some hosts — such as “Fox & Friends” host Steve Doocy and Sean Hannity — are defending the vaccine, Carlson and fellow prime-time host Laura Ingraham are undercutting them with innuendo and scare programming. A Fox News public service announcement launched on Wednesday night to promote coronavirus vaccines. The same day, Carlson bashed CNN for taking a position on the vaccine: “Why is a news channel doing this? Any news channel? A lot of them are.”

Nothing new here — Fox News pursued the same bifurcated approach to the claims that the 2020 presidential election was stolen from Trump; some programs promoted the “big lie,” and others debunked it.

If the people Carlson claims to despise are zigging, he must zag. That’s as good an explanation for his nightly ranting as any, especially considering that he has conceded, “I don’t even have politics, I just have reactions to things.” Sounds like an accurate self-diagnosis.