Figure 7: Immune responses in chickens immunized with partial purified HA proteins produced in silkworm pupae. The partially purified HA vaccine was injected subcutaneously into eight 1- month old female chickens. The same amount of HA antigens further injected on day s 0, 17, 31, 45 and 55 were subjected to conventional HI test. As a result, HI antibody titers increased linearly and reached 4,096 on day 31 and gradually declined. In spite of this decline, their high titer retained even after 55 days (A). Silkworm pupae injected with recombinant were shown in Figure 7. They activity survived during experiment.