The present invention is directed to a mutated recombinant herpesvirus, e.g.,
varicella zoster virus (VZV) and simian varicella
virus strains or HSV-1 or HSV-2 strains, vaccines containing, and methods for the construction and use thereof to elicit
protective immunity in susceptible individuals, wherein the particular herpesvirus is modified to render the
virus replication deficient, i.e., the
virus substantially or only replicates under defined conditions, by the incorporation of at least one destabilization domain in or fused to a
gene essential for herpesvirus replication. The invention particularly relates to the use of the
resultant conditionally replication defective herpesviruses, e.g., a mutated VZV strains in vaccine compositions in order to immunize individuals against
herpesvirus infection, e.g., in the case of VZV
chickenpox and to protect against
shingles and zoster, or to prevent the reactivation of VZV or other herpesvirus reactivation and the onset of
shingles or another condition relating to the reactivation of another
herpesvirus infection, e.g., as a consequence of advanced age, stress,
inflammation,
drug or other therapy,
cancer, or
immunodeficiency such as in HIV-AIDS or other diseases resulting in impaired T and / or
B cell immunity.