Earlier quoted context omitted.
They are alarming based on the measure of Observed vs. Expected cases. Observed (O) cases in that age group: 283 Expected (E) cases in that age group: 10-102 So at least double the top of the confidence interval, for expected.
but that's out of 13m doses, so ~200 out of 13m. I'm not sure how that compares to the expected harm from catching covid but I imagine the vaccine still ends up massively favourable
Also, underreporting is a factor - not everyone knows about VAERS, not everyone goes to the Dr. for chest pain etc.
I agree it's favorable, but it's important to understand the effects of any medicine on subgroups of a treatment population.