[elcritch]

Thanks, good to know about pericarditis. I’m not well versed on that or myocarditis and in particular the IgG or T-Cell response mechanism. Though the little I’ve read seems to indicate myocarditis is still primarily due to an acute immune response, but can re-occur or turn into a more autoimmune condition (chromic myocarditis or perhaps pericarditis).

That said I would normally give the benefit of doubt that the authors of a paper in the Lancet are more well versed on myocarditis and it’s behavior. It looks like they do adjust all their comparisons to odds ‘per 100,000 person-days’. If done properly that would adjust from an event basis to per-time basis or rate which could account for long tail reactions.

Using 90 days would risk including non-vaccine related myocarditis risks as well, which is perhaps why the lancet paper uses the time rate basis. If someone got a normal cold after a month and got pericarditis that'd skew the results as an example. Though I was disappointed to not see statistical analysis or comparison to normal occurrence rates of myocarditis without vaccine exposure, etc. though I didn’t thoroughly check their references, etc.