Abstract
Various procedures for immunoprotection in the A-SW mouse SEWA tumour system were compared. Four types of protector agents were used: polyoma virus, allogeneic S724 cells, A9/SEWA hybrid cells and xenogeneic ST(py) cells. Several injection schedules were also employed. On the whole, reasonable immunoprotection was obtained. The results, when allogeneic hybrid or xenogeneic cells were used, were comparable with those obtained for polyoma virus. This indicates that the T.A.T.A. of the SEWA tumour had been well conserved. When polyoma virus alone was used as the protector agent, injection 7 days before the tumour challenge, or iterative injection, afforded better protection than a single injection on the day of challenge.