PASSIVE PROTECTION OF PIGLETS BY RECOMBINANT BACULOVIRUS INDUCED TRANSMISSIBLE GASTROENTERITIS VIRUS-SPECIFIC ANTIBODIES

Sera of pigs immunized with parts of the transmissible gastroenteritis virus (TGEV) spike (S) protein expressed by recombinant baculoviruses were tested, together with a TGEV hyperimmune antiserum, for their ab ilities to protect three-day-old piglets against TGEV infection, The p iglets were infected with virulent TGEV and the sera were given orally 3 h before infection, together with the virus, and every 6 h postinfe ction during the 30 h of the experiment, Virus shedding was monitored by TGEV isolation from rectal swab samples, The sera containing antibo dies induced by the complete S protein or the amino terminal half of t he S protein showed protective properties, indicated by delayed onset of clinical signs and virus shedding, similar to the TGEV hyperimmune serum, Those immune sera containing antibodies induced by shorter reco mbinant proteins were not protective.