beatadje

In summary, we have found that deletion of the ICP34.5
open reading frame from McKrae, a highly virulent HSV-1
strain, results in an avirulent virus that is severely restricted for
growth in eyes and TG and probably establishes latency at a
reduced rate. Despite these impairments, this mutant was still
capable of low levels of spontaneous reactivation in the rabbit.
This may be an important consideration with respect to the use
of ICP34.5 deletion mutants as genetically engineered HSV
vaccines.

http://jvi.asm.org/cgi/reprint/69/5/3033?view=reprint&pmid=7707530