Russell's viper toxoid: Pattern of antibody response following immunisation with toxoid in rabbits

A prospective study of the development and persistence of antibody following immunisation with Russell;s viper toxoid was carried out in rabbits. Two immunisation schedules, each consisting of 3 injections of the toxoid given at 0, 4 and 8 weeks and at 0, 6 and 30 weeks were studied. Booster injections were given at 24 and 60 weeks in the former and at 50 weeks in the latter. The pattern of antibody response of the two immunisation schedules was comparable. Peak antibody response was maintained for 8 weeks after the third injection. No antibody response was observed following boosting at 30, 50 and 60 weeks. Use of aged toxoid and timing of boosting may play an important role in induction of subsequent antibody responses.