COVID-19 vaccinated individuals may be ill…See more

The team went further, using a cutting-edge technology developed in Wu’s laboratory. Human skin or blood cells can be transformed into blank stem-like cells and then guided to differentiate into heart muscle cells, macrophages, and the cells that line blood vessels. These cells can then be assembled into tiny spherical structures that mimic the beating, contracting behavior of actual heart tissue — what the researchers call “cardiac spheroids.”

When these cardiac spheroids were treated with cytokine-enriched fluid from vaccine-stimulated immune cells, markers of cardiac stress increased significantly and the spheroids’ ability to contract rhythmically was impaired. When cytokine inhibitors were applied, much of this damage was reversed.

A Soybean Compound Enters the Picture
Having mapped out the mechanism of injury, Wu and his team turned to a question with practical implications: could anything be done to prevent it?

Wu had a hypothesis rooted in an earlier line of research. He had previously studied a compound called genistein — a naturally occurring, mildly estrogen-like substance found in soybeans — and found it to have notable anti-inflammatory properties. That work, published in the journal Cell in 2022, had shown genistein’s ability to protect blood vessels and heart tissue from a different kind of inflammatory insult.

The connection to myocarditis seemed plausible for several reasons. The condition disproportionately affects males, and estrogen is known to have anti-inflammatory effects. Genistein, which mimics estrogen only weakly, might offer some of those protective benefits without the hormonal side effects of stronger compounds.

Wu’s team ran a parallel series of experiments in which cells, cardiac spheroids, and mice were pretreated with genistein before being exposed to the vaccine or the CXCL10 and IFN-gamma combination. In each case, genistein significantly reduced the damaging effects on heart tissue.

The version of genistein used in these experiments was considerably purer and more concentrated than what is available in typical dietary supplements. Wu acknowledged this distinction while noting the compound’s fundamental safety profile. “Nobody ever overdosed on tofu,” he remarked.

Broader Implications for mRNA Technology
The Challenges of Global COVID-19 Vaccination