The present disclosure relates to a method for the cultivation of primary cells. The primary cells are cultivated in a serum free medium supplemented with peptides and peptones derived from plant or vegetable sources. The method for the cultivation of primary cells may be one step in a method for the amplification of viruses, such as poxviruses.

Methods of producing, propagating and multiplying viruses, methods of identifying the presence of a virus in a sample, specifically methods using Japanese eel cell cultures. Also provided are an isolated Japanese eel cell culture, optionally infected with a virus, vaccines comprising viruses grown according to the methods of the invention, and a kit for propagating viruses comprising the Japanese eel cell culture. The virus may be a fish virus such as nodavirus, Infectious Pancreatic Necrosis Virus (IPNV) and Salmon Pancreas Disease Virus (SPDV).

Methods of producing, propagating and multiplying viruses, methods of identifying the presence of a virus in a sample, specifically methods using Japanese eel cell cultures. Also provided are an isolated Japanese eel cell culture, optionally infected with a virus, vaccines comprising viruses grown according to the methods of the invention, and a kit for propagating viruses comprising the Japanese eel cell culture. The virus may be a fish virus such as nodavirus, Infectious Pancreatic Necrosis Virus (IPNV) and Salmon Pancreas Disease Virus (SPDV).

The present invention relates recombinant viruses and the uses thereof. More particularly, the invention relates to novel recombinant Marek's disease viruses encoding polypeptide(s) of interest, and their use to express or deliver such polypeptides to animals, particularly poultry. The invention is particularly suited to vaccinate poultry against avian pathogens.

A method includes cultivating primary cells in a serum-free medium supplemented with peptides and peptones derived from plant or vegetable sources. The method for the cultivation of primary cells may be one step in a method for the amplification of viruses, such as poxviruses.