Medical coding for unvaxxxed:

https://www.icd10data.com/ICD10CM/Codes/Z00-Z99/Z20-Z29/Z28-/Z28.21

Immunization not carried out because of patient refusal

https://www.icd10data.com/ICD10CM/Codes/Z00-Z99/Z20-Z29/Z28-/Z28.20

Immunization not carried out because of patient decision for unspecified reason