Active immunization with feline leukemia virus envelope glycoprotein suppresses growth of virus-induced feline...

The efficiency was examined of immunization with feline leukemia virus glycoprotein complexes (gp85 rosettes) to protect cats against tumors induced by feline sarcoma virus (FeSV). The glycoprotein was isolated from feline leukemia virus (FeLV). Young cats were vaccinated with the purified viral glycoprotein and challenged with FeSV (FeLV). FeLV gp85 antibody levels were measured by enzyme-linked immunosorbent assay and tumor volumes were determined. In immunized animals tumor development was reduced. Gp85 antibody levels before challenge were correlated inversely with tumor size (r2 = 0.79). This method appears to be suitable for fast and efficient testing of future FeLV vaccines.