While the benefits of vaccination substantially outweigh the risk of this relatively rare outcome (5.8 per million), clinicians should be alert to this possible adverse event, as six out of seven patients progressed to areflexic quadriplegia and required mechanical ventilatory support.

Wait... isn't that exactly what they're trying to prevent?

With reference to your question about why this is only now being reported, I believe in that interview with Dr. Malone, the other guest made a reference to a Facebook group for people harmed by the vaccine, which had over 200,000 members as I recall, was deleted by Facebook. That certainly doesn't help.

They also talked about the dysfunctional state of the reporting system in the US.