Symptomatic pericarditis after influenza vaccination https://www.sciencedirect.com/science/article/abs/pii/S0012369215351837 https://www.sciencedirect.com/scie

Symptomatic pericarditis after influenza vaccination https://www.sciencedirect.com/science/article/abs/pii/S0012369215351837 https://www.sciencedirect.com/science/article/abs/pii/S00123... Post-vaccination myositis and myocarditis in a previously healthy male https://aacijournal.biomedcentral.com/articles/10.1186/s13223-016-0114-4 https://aacijournal.biomedcentral.com/articles/10.1186/s1322... Takotsubo cardiomyopathy after anti-influenza vaccination: catecholaminergic effects of immune system https://www.ajemjournal.com/article/S0735-6757(13)00416-6/fulltext https://www.ajemjournal.com/article/S0735-6757(13)00416-6/fu... Acute Fulminant Myocarditis Following Influenza Vaccination Requiring Extracorporeal Membrane Oxygenation https://www.ajemjournal.com/article/S0735-6757(13)00416-6/fulltext https://www.ajemjournal.com/article/S0735-6757(13)00416-6/fu... (and influenza isn't a novel virus and everyone will have already had their immune systems 'tested' by influenza antigen early in their life)