Pfizer knew their injections would damage the hearts of teens; they kept going anyway.
And when over 1200 deaths were reported in the first 90 days, Pfizer concluded its shot "does not raise new safety issues."
Everything Pfizer, and as such, what the FDA knew, is all thoroughly documented here:
https://dailyclout.io/product/war-room-dailyclout-pfizer-documents-analysis-volunteers-reports-book-paperback/