• Vaccine Name: REV gp90 Vaccine
• Target Pathogen: Reticuloendotheliosis Virus
• Target Disease: Tumors, wasting syndrome
• Type: Recombinant vector vaccine
• Status: Research
• Host Species for Licensed Use: None
• Antigen: gp90 (Ren et al., 2018)
• env gene engineering:
  • Type: Recombinant protein preparation
  • Description: encodes the surface glycoprotein (gp90) (Ren et al., 2018)
  • Detailed Gene Information: Click Here.
• Immunization Route: Intramuscular injection (i.m.)
• Description: gp90 protein-based vaccine derived from a Reticuloendotheliosis virus strain isolated from a contaminated IBD vaccine induces protection in chicks. (Ren et al., 2018)

Chicken Response

• Vaccination Protocol: Twenty 150-day-old SPF chickens were obtained from SPAFAS and randomly divided into two groups. Each chicken of immune group was immunized with 600 μg gp90 protein and 300 μg CPG-ODN. The control group was immunized with an equal volume of PBS and immunized once every two weeks (150, 164, 178, 182 days age). Eggs were collected from the immunized hens and REV-specific antibody was measured in the egg yolk. (Ren et al., 2018)
• Immune Response: Starting from the second week post-immunization, the REV antibody titer of the immunized hens increased rapidly, especially from weeks 6 to 8 post-immunization. The positive rate of antibody reached 100% and the antibody titer peaked at week 9 post-immunization. Three eggs were collected from each hen to determine if the egg yolks contained REV-specific antibody were consistent with the serum antibody test results. Hens in the control group were always antibody negative. (Ren et al., 2018)
• Challenge Protocol: Ten hatched 1-day-old chicks from the two experimental cohorts, which were REV maternal antibody positive or negative, were challenged intraperitoneally with 102.7 TCID50 of the REV-LN1201 strain. (Ren et al., 2018)
• Efficacy: At the sixth week after challenge, compared to five chicks in the control group, only one chick in the immunized group was viremic. One of the chicks in the control group died without any specific symptom during the sixth week. The presence of maternal antibodies in the chicks significantly affected the health and survival of chicks after REV infection, as supported by chicks in the control group always having a lower bodyweight than chicks in the immunized group. (Ren et al., 2018)