Clinical and macroscopic post mortem examinations did not reveal any sign of clinical manifestation of the infection. specific antibody response. Challenge experiment with PCV2 carried out in immunized pigs showed partial protection against the infection. Based on these results it was concluded that specific antiviral vaccine production for the given pathogen was feasible, offering an inexpensive way for the mass production of such vaccines. Introduction Vaccines have been revolutionary for the prevention of infectious diseases especially in case of computer virus induced clinical conditions. Beside the continued development of the inactivated or live attenuated vaccines, major efforts are invested in subunit vaccines  for either mucosal or parenteral delivery to overcome shortages of the traditional types. Subunit vaccine refers to pathogen-derived antigens, sometimes limited to one or more immunogenic domains of a protein, which cannot cause disease but can, activate the host immune response system against the pathogen. A special area of subunit vaccine production is offered by the use of plants, either as transgenic plants or as natural media for the propagation of recombinant herb viruses expressing a GW788388 desired gene of GW788388 an animal or human pathogen. Such vaccines, also as edible ones, have been at the focus of research since the first report of transgenic tobacco plants expressing hepatitis B surface antigen (HBsAg) , proving that HBsAg can stimulate mucosal immune responses via the oral route . Using comparable approaches a number of important veterinary pathogens were targeted and the vaccines showed promising results after oral or parenteral application C. Plant derived antigens offer several advantages over traditional vaccines, including stability, increased safety, rapid and massive production, cost effectiveness and especially in case of plant seeds long term storage and long distance shipment at variable temperatures C. The pioneering work of Lomonossoffs group on a versatile plant computer virus expression system based on the icosahedral cowpea mosaic computer virus (CPMV) gave a burst to the development of alternative expression systems from herb RNA viruses C. One of the first such experiments used CPMV Rabbit Polyclonal to TPH2 (phospho-Ser19) after the crystal structure of the computer virus GW788388 particle had been resolved, allowing for the precise insertion of the epitopes into the coat proteins C. The number of comparable expression systems using herb viruses is constantly increasing . Recently cucumber mosaic computer virus (CMV) was considered as a potential vector for expressing foreign epitopes , . Furthermore, CMV is usually a promising candidate as an oral vaccine, since it has an extremely wide host range, and accumulates in substantial amount in different parts of the plants, like leaves, fruits, tubers and roots. A target of plant computer virus based vaccine development is suggested in the present study, namely against porcine circovirus (PCV) infections. PCV is one of the smallest known animal viruses; it belongs to the genus of the family. It is non-enveloped with a single-stranded circular DNA genome surrounded by a capsid built of the only structural protein of the computer virus (the capsid protein) that is also the main target of antiviral immune response C. Two species of PCV have been identified so far, PCV1  originally isolated as a cell line contaminant and PCV2 that is strongly immune suppressive and is responsible for a number of clinico-pathological conditions, referred to as PCV associated diseases (PCVD) . PCV2 is present worldwide causing major economic losses in the pig industry. The control of the infection and PCVDs is crucial and traditional inactivated or subunit vaccines using baculovirus expression systems had been developed and commercialized. The efficacy of the available vaccines, based on the average.