Lactogenic immunity to transmissible gastroenteritis virus induced by a subunit immunogen.

A subunit prepared from transmissible gastroenteritis (TGE) virus and used to immunize 24 gilts prior to farrowing induced production of specific antibody in the serum and milk. Challenge of pigs, two to seven days of age and suckling on the vaccinated gilts, with the Illinois strain of TGE virus resulted in morbidity of 28% and mortality of 4% as compared with 100 and 73%, respectively, for control piglets. Piglets nursing on a sow which had been immunized approximately 10 months previously were not protected, indicating that lactogenic immunity may be of short duration. Revaccination of this animal resulted in an anamnestic response.