Active and passive immunisation against nephritis induced by an avian infectious bronchitis virus.

Intranasal vaccination with the H120 strain of infectious bronchitis virus (IBV) produced serum neutralisation indices of three or more in nine out of 12 birds. This afforded complete protection against intravenous challenge with the nephritogenic H52 strain of IBV and prevented the multiplication of virus in the kidney. Passive immunisation with homologous convalescent serum protected the kidney but not the respiratory tract against similar challenge. The frequency of virus isolations from the kidney was reduced, the agar gel precipitin response lowered and the haemagglutination inhibition response abolished.