My guess would be an undiagnosed case of HLH, which leads to your NK cells not functioning properly. https://www.dana-farber.org/childhood-hemophagocytic-lymph

My guess would be an undiagnosed case of HLH, which leads to your NK cells not functioning properly. https://www.dana-farber.org/childhood-hemophagocytic-lymphohistiocytosis/ https://www.dana-farber.org/childhood-hemophagocytic-lymphoh... I'm betting the vaccine triggered the cytokine storm, rather than a virus itself which the most common triggering event. It's such a rare disease that by the time it's diagnosed, it's too late to intervene with steroids and chemo drugs to stop the runaway immune system.