Abstract
In a previous communication it was reported that Japanese B encephalitis virus was combined in vitro with the specific virus-neutralizing antibodies of the hyperimmune horse sera (Kawakita & Tazaki). Curiously enough, there seemed to be no absorption or blocking effect to antibodies contained in the sera of animal other than horses. According to the presents author's opinion, the seemingly qualitative species difference lies in the firmness of the antibody-virus combination. Antibodies in horse sera combine exceptionally firmly with the virus in vitro, so that blocking effect can be readily observed, irrespective of the methods of inactivation of virus, whereas with the sera of rabbits, mice, etc., heat Inactivation causes the dissociation of the virus-antibody combination once actually established. Experiments which led to the above conclusion were presented in detail
