This story bears watching. It has long been theorized that the mRNA vaccines created for Covid-19 might themselves cause vascular disease. We may now be seeing evidence to support that speculation. There are also ethical questions to work through. Even if the risk of myocarditis or pericarditis is low, is it ethical to vaccinate children and young adults who, as a group, face little risk from Covid-19 as well as pose little risk to others?