It's most dangerous for teenage boys, but yes, it's still dangerous for people of all ages.
My little brother is in his mid 50s and was a captain for Southwest Airlines for over 20 years. He got the Pfizer shots and a few weeks later he was grounded for a swollen and inflamed heart when he went in for his FAA physical. He has now been told that he will not be able to fly again because the damage caused is apparently permanent. He knows other pilots who have been grounded for the same reason. We are told that it is a problem mostly for teenage boys which is bologna. The heart problems are not always noticed and are likely much more prevalent than is currently presumed.
Have heard similar stories in our circle.
It's most dangerous for teenage boys, but yes, it's still dangerous for people of all ages.