Determination of live duck plague vaccine efficacy based on PD50 and correlation between TCID50 and PD50

Abstract

Live Duck Plague (Duck Virus Enteritis – DVE) vaccine produced by Hanvet Company from 2013 up to date (2015) was determined for its efficacy through PD50 in 3 different times in 3 years with 7 plots/batches on duck (0.7 – 1 kg/duck). The studied result showed that the efficacy of this vaccine was stable. With the virus content was only from 3.16 TCID50, 100% ducks were protected when challenge test with 1000 DLD50. Meanwhile, at present this vaccine contented ≥1000 TCID50/ dose. Therefore, 100% ducks were protected steadily with the use dose. The studied result also indicated that the correlation between virus titer and PD50 was closely favourable. Virus content from 3.16 to 7.9 TCID50 = 1PD50