author wrote..

This is the primary reason I am not all that concerned about a Marek's sort of nasty. The "N" part of the protein is well-conserved and, in addition, there is material pre-existing cross-reaction in the population we've known about since Diamond Princess, and known why since last summer on a conclusive scientific basis.

The jabs may well damage or destroy a good part of that protection, but in the unjabbed if you had it you still do, whether you acquired it by natural infection or cross-reactivity from some other virus you encountered.