The first time around he was told that he would not be able to get a waiver because he supposedly already had permanent damage. But miraculously the airline found a “Flight Surgeon” several states away that was writing waivers for this condition, and he was allowed back in the cockpit. After the “booster” his condition worsened immediately to the point that he will be lucky if he lives
It's not clear in your description (and it's none of my business anyway) if your brother's condition actually improved (after the first two shots) or if the out-of-state flight surgeon approved him because he didn't think this should ground him.
In any event, if he had a swelling and enlargement of the heart I would think that not only would that mean he would require a medical waiver to fly, but that it would mean he couldn't take another shot on top of the two he took.
sorry to hear that bro. I know several of my colleagues quit a certain studio due to the mandates. They have smartly, been involved in multiple streams of income so they can do this.