Meleagrid alphaherpesvirus 1 (HVT) (HVT)

Marek's disease virus serotype 3 (MDV-3), also known as Herpesvirus of turkeys (HVT) or Meleagrid alphaherpesvirus 1, is a non-pathogenic avian herpesvirus belonging to the Mardivirus genus [1, 16]. It was originally isolated from turkeys and is widely used as a live vaccine in the poultry industry to protect chickens against the highly oncogenic Marek's disease virus serotype 1 (MDV-1) [1, 9]. HVT establishes a persistent, life-long infection in chickens without causing clinical disease or tumors, providing protection by inducing a robust immune response that interferes with the pathogenesis of virulent MDV strains [12, 19]. In addition to its use as a primary vaccine, HVT serves as a versatile recombinant viral vector for expressing antigens from other poultry pathogens, such as Newcastle disease virus (NDV) and infectious bursal disease virus (IBDV) [9, 12, 19]. While HVT is highly effective at preventing lymphoma formation, it does not prevent infection or shedding of pathogenic MDV-1, and concerns exist regarding potential recombination with other herpesviruses in the field [1, 9, 16]. Although HVT is primarily used as a vaccine, its replication can be inhibited by antiviral drugs such as acyclovir, which targets the viral DNA polymerase [10]. Furthermore, host innate immune pathways, specifically the Toll-like receptor 3 (TLR3) pathway, have been shown to restrict HVT infection, suggesting potential avenues for enhancing vaccine efficacy through the use of TLR agonists [2, 11].

Other names

Herpesvirus of turkeysMarek's disease virus serotype 3MDV-3Turkey herpesvirusMeHV-1

Inhibition of viral DNA polymerase; Activation of Toll-like receptor 3 (TLR3)