Dear Colleagues, I do not think that there is a need of species specific vaccine. I my opinion, the difference in sero-conversion also suggests that sheep is relatively more resistant (poor seroconversion) to PPR than goat, as live vaccine induces immunity by limited viirus replication within the body. It is also possible that a low level of antibody in sheep may provide equivalent level of protection with higher level of antibody in goat. regards, R.P.Singh Dr. R.P.Singh, Principal Scientist, Division of Biological Products, Indian Veterinary Research Institute, Izatnagar, Bareilly-243 122 (Uttar Pradesh), India Alternate email: [log in to unmask] Mobile:+91-9412360917 ----- Original Message ----- From: Paul Rossiter Sent: 02/07/14 09:28 PM To: [log in to unmask] Subject: From Dr Srinivasan on the possible need for species specific vaccines Dear Colleagues, When we first developed PPR Sungri/96 vaccine, during the initial field evaluation of vaccine we observed goats were better sero-converters than Sheep. In a study involving more than 500 post-vaccinate sera samples in each of the species, we observed 98% sero-conversion in goats and 83% in sheep. Even the VN titer was lesser in sheep than goats (eg., most of the goats had 1:64 to 1:128 and sheep it was 1:32 to 1:64). PPR Sungri/96 virus which was used to develop attenuated vaccine was originally rescued from post-mortem samples from a goat died in the PPR outbreak. Does this suggests that we should have separate vaccine candidates for sheep and goat? I must confess I am not keeping abreast of PPR literature as I have moved away from PPR research almost 11 years back. Regards Srinivas I hope that several of you will give us your views on this radical idea - moderator ________________________________ Dr.B.P.Srinivas Principal Scientist Indian Veterinary Research Institute (IVRI) Hebbal, Bangalore-560024 India Tel: 91-80-23410729 (Work) Fax: 91-80-23412509 ----------------------------------------------------------------- To unsubscribe from the FAO-AnimalHealth-L list, click the following link: https://listserv.fao.org/cgi-bin/wa?SUBED1=FAO-AnimalHealth-L&A=1 ######################################################################## To unsubscribe from the FAO-AnimalHealth-L list, click the following link: https://listserv.fao.org/cgi-bin/wa?SUBED1=FAO-AnimalHealth-L&A=1