Research Progress of the Diagnostic Techniques and Vaccines for PRRS
Porcine reproductive and respiratory syndrome(PRRS)has brought huge economic losses to pig production in the world,which should be prevented and controlled with the top priority of accurate detection and scientific application of vaccines. At present,the main techniques to diagnose PRRS included serum antibody ELISA assay and various RT-PCR assays. The former aims to evaluate the immune effect of vaccines or wild virus infection,while the latter focuses on clinical diagnosis and investigation of wild virus strains. For vaccines,all kinds of single and combined vaccines are available in markets,including live vaccines,inactivated vaccines,subunit vaccines,DNA vaccines,vector vaccines,etc.,specifically,live vaccines are with good effect but poor cross protective immunity;inactivated vaccines are with high safety but poor immune effect;subunit vaccines can be used in late pregnancy;DNA vaccines can increase the protection effect of live vaccines;and vector vaccines have not been applied in practice although they are with partial protective immunity. No any vaccines against PRRS that fully meet the new international standards have been available till now. Therefore,it will be very crucial to control PRRS in farms or regions through scientific diagnosis and combination of bio-safety and reasonable vaccination to detect field strains and analyze their genes,and then to vaccinate with corresponding vaccines.