Inactivated whole virus. Virus is most usually grown in suspension cultures of the baby hamster kidney cell line within sealed containers in contained labs. The virus is inactivated by azuridines which cross-links the nucleic acid without affecting the capsid antigens. Formalin inactivation is no longer licensed in certain countries because some such european vaccines eg Normandy 1981 caused infection of pigs.

Vaccines are tested for residual infectivity by intra-dermo-lingual inoculation of cattle and for protection by failure of vesicle formation. Three times the protective dose is usually used for reasons of economy (cf 100 protective doses with some other vaccines).

Vaccination is usually repeated every 6-12 months. Adjuvants to reduce antigen include alhydrogel with saponin (crude Quill-A) for cattle ( this does not work in pigs), or oil for pigs.

[Attenuated vaccines revert to virulence. Peptide vaccines have worked in guinea-pigs but not cattle.]