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The hybrid baculovirus constructed from Autographa california nuclear polyhedrosis virus (NPV) and Bombyx mori (silkworm) NPV was used for expression of fusion glycoprotein (F) of Newcastle disease virus (NDV) strain D26. The gene encoding F protein was introduced into the improved baculovirus expression vector derived from the host-range-expanded baculovirus. In Spodoptera frugiperda (fall armyworm) cells infected with a recombinant baculovirus, HyF121, the expressed F protein was properly located onto the cell surface. After silkworm pupae were infected with HyF121, a subunit vaccine against NDV was prepared from the HyF121-infected pupae. Chickens inoculated with the subunit vaccine were protected against virulent NDV challenge.

Five trials were conducted to compare four in vitro methods of isolating avian infectious bronchitis virus (IBV)-direct organ culture of infected tracheal rings (DOC), inoculation of tracheal organ culture (OC), inoculation of chicken embryo, and inoculation of cultured cells. DOC was prepared from tracheas of chickens experimentally inoculated with field samples. In the other methods, pooled tracheal and kidney suspensions were used to inoculate OC, chicken embryos, and cultured cells. IBV was consistently isolated at the initial passage by the DOC and OC inoculation systems, but it was not always isolated by embryo inoculation and never isolated by cultured-cell inoculation. When combined with immunofluorescent staining, DOC was much more efficient than the OC inoculation system for isolation and identification of the five strains of IBV tested because of its simplicity and speed.