[Study of the correlation between the plasma viral load and protective immunity induced by the equine infectious anemia attenuated vaccine and its parental virulent strain].
The threshold hypothesis of attenuated lentiviral vaccine considers that the type of host response to infections of lentiviruses depends on the viral load. To evaluate the correlation between viral loads of the attenuated vaccine strain of equine infectious anemia virus (EIAV) and their effects to induce protective immunity, longitudinal plasma viral loads in groups of horses inoculated with either an attenuated EIAV vaccine strain (EIAV(DLV125)) or sub-lethal dose of an EIAV virulent strain (EIAV(LN40)) were compared. Similar levels of plasma viral loads ranging from 10(3)-10(5) copies/mL were detected from samples of these two groups of animals (P > 0.05) during 23 weeks post the inoculation. However, different responses to the challenge performed thereafter with lethal dose of the EIAV virulent strain were observed from the groups of horses inoculated with either EIAV(DLV125) or sub-lethal dose of EIAV(LN40). The protective efficiency was 67% (3 of 4 cases) and 0 (none of 2 cases), respectively. Our results implicate that the viral load of EIAV attenuated vaccine is not the primary factor, or at least not the solo primary factor, to determine the establishment of immune protection.
Cao
Xue-Zhi
XZ
State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Division of Livestock Infectious Disease, Harbin 150001, China.
Lin
Yue-Zhi
YZ
Li
Li
L
Jiang
Cheng-Gang
CG
Zhao
Li-Ping
LP
Lv
Xiao-Ling
XL
Zhou
Jian-Hua
JH
D000818:Animals; D004859:Equine Infectious Anemia / Q000097:blood / Q000276:immunology* / Q000517:prevention & control; D006736:Horses; D007114:Immunization / Q000379:methods; D004860:Infectious Anemia Virus, Equine / Q000276:immunology* / Q000472:pathogenicity; D012367:RNA, Viral / Q000097:blood / Q000235:genetics; D011897:Random Allocation; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000276:immunology*; D019562:Viral Load; D014765:Viral Vaccines / Q000008:administration & dosage / Q000276:immunology*; D014774:Virulence / Q000276:immunology
D012367:RNA, Viral; D014613:Vaccines, Attenuated; D014765:Viral Vaccines