[Studies of 2-mercaptoethanol sensitivity of the antisera against Japanese encephalitis virus. 4. Relationship between inoculum size and antibody production in artificially inoculated swine].

In their previous paper, the authors mentioned that the duration of production of 2-Mercaptoethanol (2ME)-sensitive antibody against Japanese encephalitis virus was variable in naturally infected pigs. In order to elucidate the relationship between the virus dose and the duration of 2ME-sensitive antibody production, pigs were inoculated experimentally with varying doses of Japanese encephalitis virus. Some of them were inoculated subcutaneously with 1ml of 10-1 or 10-2 dilution and 1ml of 10-4 or 10-5 dilution of a pooled virus of 107.3 LD50/0.03ml, and found to produce 2ME-sensitive antibody for two and four weeks, respectively. After these periods, the antibody became 2ME resistant. Thus, the results obtained from this experiment indicate that the larger the dose of inoculum given, the sooner 2ME-resistant antibody was produced. They may explain the difference in antibody response between the naturally infected pigs in 1966 and those in 1967.