If she’s had covid, she’s got the best antibodies of all.
Except that, like the rest of our bodies, typically as one ages our immune systems wear down. A heavy hit can just set one up for the next infection, esp. if it is a different variant or another disease. I found this out with my Dad.
A sort of opposite scenario can occur when a light infection is quickly suppressed: Fewer antibodies are generated, fading to ineffectiveness in as soon as several months, and an effective force of memory cells may not be generated at all. No need to build a huge force to ward off Bulgaria, right? But then a heavy exposure may overwhelm the light defense remaining.
If Gov. Palin got moderately ill (like a flu case knocking her down for a few days) on the 1st round, she may well fit your description. In any event, I wish her the best!