Marek’s disease herpesvirus vaccines integrate into chicken host chromosomes yet lack a virus-host phenotype associated with oncogenic transformation

Highlights • Marek’s disease (MD) incidence is reduced with HVT, SB-1, and/or Rispens vaccination. • The physical status of MD vaccines at the level of the host genome was not known. • We provide an overview of the cytogenetic interactions of MD vaccines with the host. • Our data show that MD vaccines are capable of integrating into the host genome. • However, MD vaccines lacked a virus-host phenotype observed for oncogenic MDV.