Too old AND too young.

Not all that long ago I was smitten by "something". Eventually I saw the medic, just in time to ask "Have I just had Shingles?"
More recently I discovered there is a Vaccine which I am simultaneously too old and too young to receive.
I'll admit to snatching figures out of the air, but it runs something like this... "You" are eligible if you are between, say, 65 & 70 or 80 & 85 when I was 71.
Goal posts move "now eligible if between 66 & 71 or 79 & 84; I am "now" 72  and not eligible.
They are performing a pincer movement, evidently.
I suspect I'll be eligible by the time the spread is between 70 & 75 or 76 & 81.
Or something like that.