• Vaccine Name: Chicken Anemia Virus GD-G-12 Vaccine
• Target Pathogen: Chicken Anemia Virus
• Target Disease: Chicken infectious anemia, Blue wing disease, Anemia dermatitis syndrome, Hemorrhagic aplastic anemi
• Type: Live, attenuated vaccine
• Status: Research
• Host Species for Licensed Use: None
• Antigen: GD-G-12 strain (Zhang et al., 2015)
• Preparation: Two CAV strains GD-G-12 (GenBank accession number: KF224931) and GD-E-12 (KF224929) were isolated from a commercial farm in southern China and have been previously described. The viruses were propagated in MDCC-MSB1 cells in RPMI-1640 medium supplemented with 10% fetal calf serum plus, 100 μg/mL kanamycin sulfate, and 1 μg/mL Fungizone. The cells were cultured in bottles in an incubator at 37 °C. (Zhang et al., 2015)
• Immunization Route: Intramuscular injection (i.m.)
• Description: CAV GD-G-12 inactivated vaccine induces high titers of CAV specific antibodies and resistance to CAV challenge in hens. (Zhang et al., 2015)

Chicken Response

• Vaccination Protocol: The levels of maternal CAV antibodies passed from vaccinated hens to their chicks were measured. Ninety SPF hens at one day old confirmed free of CAV antibodies were purchased and divided into two groups (n = 30/group). Hens in the experimental group were vaccinated intramuscularly with 1 mL of the inactivated vaccine (7.9 × 10^17 copy/μL). The control group was inoculated with 1 mL of PBS. Fourteen days post-vaccination, the vaccinated hens received a second immunization with 1 mL of the inactivated vaccine (7.9 × 10^17 copy/μL). Forty-two days post-vaccination, fertilized eggs were collected from each group, incubated, and hatched in an automatic incubator. After the chicks had successfully hatched (approximately 21 days), chicks (n = 80) from vaccinated hens and control hens were divided into two sub-groups and placed into separate negative pressure chicken disconnectors. (Zhang et al., 2015)
• Immune Response: Following vaccination with inactivated GD-G-12, the level of CAV specific antibodies increased, and peaked 8861 at 14 days after the second immunization. The antibody level remained elevated until 42 days after the second immunization. We next assessed whether the maternal antibodies were effectively transmitted to chicks. The antibody levels in chicks from the vaccinated and unvaccinated hens were assessed when the chicks were one day old. No CAV specific maternal antibodies were detected in chicks from the unvaccinated hens. In the chicks from vaccinated hens, the titer of CAV specific was 8518 on day 1. The levels remained detectable but started to decline on day 7 (8398), 14 (7780), and 21 (3500) after hatching. (Zhang et al., 2015)
• Challenge Protocol: One sub-group of chicks from each group was challenged intramuscularly with 1 mL of GD-E-12 (5.6 × 10^16 copy/μL) at one day old.
• Efficacy: Chicks from the vaccinated hens had a significantly greater mean body weight than chicks from the unvaccinated hens on days 7, 14, and 21 post challenge (P < 0.01). The mean thymus to body weight ratios were significantly increased in the chicks from the vaccinated hens compared to the chicks from the unvaccinated hens on days 7, 14, and 21 (P < 0.01). At day 7 post challenge the chicks from unvaccinated hens showed severe bleeding in the thymus, and at day 14 post challenge, these chicks had thymic atrophy and the thymus was yellow. Finally, by day 21 post challenge, the unvaccinated chicks had clear bloody spots in the thymus. There were no apparent signs of CAV pathology in the chicks from vaccinated hens on day 7, 14, or 21 post challenge. Similar results were observed in the histopathology studies. (Zhang et al., 2015)