Vaccinal Control of Marek’s Disease: The Present and Future - A Review

Marek’s disease is an economically relevant lymphoid neoplasm of poultry, caused by oncogenic strains of Marek’s disease herpesvirus. The disease has been controlled effectively by vaccination with attenuated or non-pathogenic MDV strains. Different vaccines have been tried out and the underlying principle for immunity is the action of antibodies targeted against membrane specific antigens and cytotoxic effect against tumor cells. Marek’s disease virus is a particularly unwieldy herpesvirus to manipulate molecularly and many of the techniques performed routinely for other herpes viruses are not yet available for the MDV machinery. The postulated mechanisms of immunity against Marek’s disease have been discussed here in detail. Vaccine breaks do occur as field strains continue to evolve towards pathotypes of increased virulence, and this evolution is of course vaccine driven. Experimental solutions to improve protection against the disease, like recombinant vaccines, have been discussed in this paper.