title: A pilot study comparing the development of EIAV Env-specific antibodies induced by DNA/recombinant vaccinia-vectored vaccines and an attenuated Chinese EIAV vaccine.
abstract: Data from successful attenuated lentiviral vaccine studies indicate that fully mature Env-specific antibodies characterized by high titer, high avidity, and the predominant recognition of conformational epitopes are associated with protective efficacy. Although vaccination with a DNA prime/recombinant vaccinia-vectored vaccine boost strategy has been found to be effective in some trials with non-human primate/simian/human immunodeficiency virus (SHIV) models, it remains unclear whether this vaccination strategy could elicit mature equine infectious anemia virus (EIAV) Env-specific antibodies, thus protecting vaccinated horses against EIAV infection. Therefore, in this pilot study we vaccinated horses using a strategy based on DNA prime/recombinant Tiantan vaccinia (rTTV)-vectored vaccines encoding EIAV env and gag genes, and observed the development of Env-specific antibodies, neutralizing antibodies, and p26-specific antibodies. Vaccination with DNA induced low titer, low avidity, and the predominant recognition of linear epitopes by Env-specific antibodies, which was enhanced by boosting vaccinations with rTTV vaccines. However, the maturation levels of Env-specific antibodies induced by the DNA/rTTV vaccines were significantly lower than those induced by the attenuated vaccine EIAV(FDDV). Additionally, DNA/rTTV vaccines did not elicit broadly neutralizing antibodies. After challenge with a virulent EIAV strain, all of the vaccinees and control horses died from EIAV disease. These data indicate that the regimen of DNA prime/rTTV vaccine boost did not induce mature Env-specific antibodies, which might have contributed to immune protection failure.
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.
authors.forename: Qinglai
authors.initials: Q
authors.lastname: Meng
authors.forename: Yuezhi
authors.initials: Y
authors.lastname: Lin
authors.forename: Jian
authors.initials: J
authors.lastname: Ma
authors.forename: Yan
authors.initials: Y
authors.lastname: Ma
authors.forename: Liping
authors.initials: L
authors.lastname: Zhao
authors.forename: Shenwei
authors.initials: S
authors.lastname: Li
authors.forename: Kai
authors.initials: K
authors.lastname: Yang
authors.forename: Jianhua
authors.initials: J
authors.lastname: Zhou
authors.forename: Rongxian
authors.initials: R
authors.lastname: Shen
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Zhang
authors.forename: Yiming
authors.initials: Y
authors.lastname: Shao
mesh_terms: D000818:Animals; D057134:Antibodies, Neutralizing / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood*; D004859:Equine Infectious Anemia / Q000517:prevention & control*; D006736:Horses; D004860:Infectious Anemia Virus, Equine / Q000276:immunology*; D010865:Pilot Projects; D016019:Survival Analysis; D014611:Vaccination / Q000379:methods; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000276:immunology; D019444:Vaccines, DNA / Q000008:administration & dosage* / Q000276:immunology*; D014759:Viral Envelope Proteins / Q000276:immunology; D014765:Viral Vaccines / Q000008:administration & dosage* / Q000276:immunology*
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D014613:Vaccines, Attenuated; D019444:Vaccines, DNA; D014759:Viral Envelope Proteins; D014765:Viral Vaccines