The techniques involved in I-2 vaccine production are relatively simple. The I-2
ND virus is inoculated into the allantoic cavity of embryonating chicken eggs at
9 or 10 days of incubation. The virus infects and grows in the cells lining the
cavity, and allantoic fluid is harvested 96 hours after inoculation when the virus
infectivity titre is high. The fluid is then processed to make I-2 vaccine. Tests to
confirm the safety and potency of the vaccine are performed throughout the
production process. A flow chart of I-2 vaccine production is shown in Figure 3.
Figure 4 repeats the flow chart and shows where each procedure may be found in
this manual.