Antigenicity of HUA-PRRS01 Virus Strain Isolated in Vietnam

Abstract

    In Marc-145 monolayer cells, PRRS virus caused cytopathogenic effect (CPE) as early as 36 hours post inoculation (35%) and reached 100% at 60 hours post inoculation. The titer of HUA-PRRS01 virus was 3.16x10⁵ (TCID50/25μl). Experimental pigs had normal body temperature and showed no unusual reactions after injecting with inactivated antigen that was produced from HUA-PRRS01 virus strain. Inactivated HUA-PRRS01 virus was able stimulate experimental pigs to produce specific antibody of PRRSV with high antibody level. They had antibody level over S/P ratio (0.4) at 14 dpi (average S/P ratio was 0.697 ± 0.271), reached a maximum at 42 dpi ( average S/P ratio was 1,197 ± 0,256), and then decreased at 49 dpi with antibody level remaining over S/P ratio of 0.4. In the present research, antigenic characteristics of HUA-PRRS01 strain virus was tested in pigs. These results are useful for selecting the virus strain for producing PRRS vaccine to minimize economical loss caused by PRRSV.