Overview
- A Stanford-led team reported elevated CXCL10 and interferon gamma in vaccine recipients with myocarditis and reproduced this cytokine surge in human immune cells and inoculated mice.
- Human cardiac spheroids exposed to these signals showed impaired contraction, and vaccinated mice had reduced cardiac injury markers when the cytokines were blocked with antibodies.
- The estrogenlike compound genistein prevented or reversed damage in mice and cell models, and the authors said it did not diminish vaccine effectiveness in their experiments.
- Surveillance data indicate the condition remains uncommon, with about 7 cases per million after first doses, higher rates after second doses, and the greatest incidence in men under 30.
- Experts emphasize that SARS‑CoV‑2 infection causes myocarditis more frequently and often more severely, and they note the new findings are preclinical with mouse studies using relatively high doses.