• Vaccine Name: IBV Vaccine SZ200
• Target Pathogen: Infectious Bronchitis Virus (IBV)
• Target Disease: Infectious Bronchitis
• Type: Live, attenuated vaccine
• Status: Research
• Host Species for Licensed Use: None
• Host Species as Laboratory Animal Model: chicken
• Antigen: GI-19 genotype vaccine strain SZ (Zhao et al., 2019)
• Preparation: The GI-19 genotype vaccine strain, SZ200, was attenuated in our laboratory with 200 serial passages in SPF embryonated chicken eggs via the allantoic sac route. (Zhao et al., 2019)
• Immunization Route: intranasal immunization
• Description: Live attenuated SZ200 vaccine protects chickens against IBV challenge. (Zhao et al., 2019)

Chicken Response

• Vaccination Protocol: Seventy-five 14-day-old SPF chickens were divided into six groups of 15 or 10 birds. Groups A (15 birds) and B (10 birds) were used as the negative controls. Groups C (15 birds) and D (10 birds) were vaccinated intranasally with 103.5 EID50 SZ200. Groups E (15 birds) and F (10 birds) were left unvaccinated. (Zhao et al., 2019)
• Immune Response: c. The unvaccinated challenged group C showed a maximum average ciliostasis score of 4, whereas the average ciliostasis score in the SZ200-vaccinated group was <2. The difference in ciliostasis was extremely significant between the SZ200-vaccinated group and the unvaccinated group (p < 0.01). Significant reductions in the postchallenge viral load in the tissues of the SZ 200-vaccinated groups were detected at 3, 5, and 7 dpc compared with those in the unvaccinated group (p < 0.05). (Zhao et al., 2019)
• Side Effects: In terms of the clinical manifestations, no gross lesions were observed in the SZ200-vaccinated group. (Zhao et al., 2019)
• Challenge Protocol: All groups were challenged intranasally with LGD at a dose of 10^6.0 EID50/bird at 14 days postvaccination. (Zhao et al., 2019)
• Efficacy: Compared with the unvaccinated challenged group (60% morbidity, 10% mortality), the SZ200 vaccine reduced the morbidity and mortality of the chickens infected with LGD. (Zhao et al., 2019)