Avian infectious bronchitis virus (IBV) is a coronavirus which infects poultry, causing the associated disease, infectious bronchitis (IB) (Wiki: Infectious Bronchitis Virus). Infectious bronchitis is an acute, rapidly spreading, viral disease of chickens characterized by respiratory signs, decreased egg production, and poor egg quality. Some strains of the causative virus, infectious bronchitis virus (IBV), are nephropathogenic. The latter strains produce interstitial nephritis resulting in significant mortality. Infectious bronchitis is of major economic importance to commercial chicken producers worldwide. IBV is shed by infected chickens in respiratory discharges and feces. The highly contagious virus is spread by airborne droplets, ingestion of contaminated feed and water, and contaminated equipment and clothng of caretakers. Naturally infected chickens and those vaccinated with live IBV may intermittently shed virus for many weeks or even months. Virus infection in layers and breeders occurs cyclically as immunity declines or on exposure to different serotypes. (Merck Vet Manual: Infectious Bronchitis).
4. Microbial Pathogenesis
Infectious bronchitis virus initially infects and replicates in the upper-respiratory tract causing the loss of protective cells lining the sinuses and trachea. After a brief viremia, the virus can be detected in the kidneys, reproductive tract, and cecal tonsils. Some strains of IBV, which are referred to as nephropathogenic are known to cause lesions in the kidney. Renal damage associated with different IB strains is an increasingly important feature of IB infections, especially in broiler chickens (Infectious-bronchitis.net).
5. Host Ranges and Animal Models
It is generally accepted that chickens are the most important natural hosts of IBV; all ages of chickens can be infected. IBV, or closely related coronaviruses have also been isolated from other species such as turkeys, pheasants, quail and partridges (Infectious-bronchitis.net).
BV-Dual-S1 expresses the S1 glycoprotein of IBV-M41 on the baculovirus envelope, and is capable of expressing it in mammalian cells (Zhang et al., 2014).
g. Immunization Route
Intramuscular injection (i.m.)
h.
Chicken Response
Vaccination Protocol:
The chickens were immunized with BV-Dual-S1 or an inactivated vaccine (Zhang et al., 2014).
Vaccine Immune Response Type:
VO_0003057
Challenge Protocol:
The immunized chickens were challenged with a virulent IBV-M41 (Zhang et al., 2014).
Efficacy:
A significant difference was not observed for protection rates between chickens immunized with BV-Dual-S1 (83%) or inactivated vaccine (89%) following challenge with virulent IBV-M41. Our findings show that the protective efficacy of BV-Dual-S1 could be significantly enhanced by baculovirus display technology (Zhang et al., 2014).
2. Bronchitis Mass Type, Live Virus Vaccine (USDA: 1231.11)
Immune Response:
Vaccination with pVAX-S1 plus pVAX-chGM-CSF induced a level of anti-IBV antibodies that was significantly higher than in animals receiving pVAX-S1 alone (P < 0.05) beginning on the seventh day after booster vaccination (Tan et al., 2009).
Efficacy:
PBS and pVAX1 immunized groups had 0% protection efficacy. The protection efficacy in the group vaccinated with the pVAX-S1 plus pVAX- chGM-CSF was 86.7%, whereas for the group vaccinated with pVAX-S1 alone, it was 73.3%. These results suggest that chGM-CSF, used as a molecular adjuvant, can improve the protection efficacy of an IBV S1 protein DNA vaccine (Tan et al., 2009).
Vaccination Protocol:
Chickens were immunized with the multivalent DNA vaccine twice and then boosted with an inactivated vaccine once (Yan et al., 2013).
Immune Response:
Antibody titers of the chickens immunized with pVAX1-16S1/M/N were much higher than those of the monovalent groups (p < 0.01) (Yan et al., 2013).
Efficacy:
A protective rate up to 90% was observed in the pVAX1-16S1/M/N group (Yan et al., 2013).
Efficacy:
Priming with a DNA vaccine encoding nucleocapsid protein (pVAX1-N) and boosting with the inactivated IBV vaccine provided up to 86.7% rate of immune protection, compared to the lack of protection seen in the PBS-immunized group, where the death rate was 66.7% (Guo et al., 2010).
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)
g. Immunization Route
intranasal immunization
h. Description
Live attenuated SZ200 vaccine protects chickens against IBV challenge. (Zhao et al., 2019)
i.
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)
46. Infectious Bronchitis Virus DNA Vaccine encoding S1, N, and M
Vaccination Protocol:
The seven day old SPF chickens were randomly divided into six groups with 20 chickens per group. Groups 1–3 received 100 micro-g of pVAX1-S1, PVAX1-M, or pVAX1-N, respectively; Group 4 received 100 micro-g combined DNA vaccine containing 33 micro-g of each of the three antigen plasmids; Groups 5–6 received 100 micro-g empty pVAX1 and 0.5 ml PBS. All the chickens were immunized intramuscularly with the vaccines at seven days of age (Yang et al., 2009).
Vaccine Immune Response Type:
VO_0003057
Immune Response:
Anti-IBV antibody levels were detected in chickens immunized with either pVAX1-S1, pVAX1-M, pVAX1-N or the three constructs in combination. In fact, a higher antibody titer level was observed in chickens immunized with the three expression constructs in combination compared with the individual constructs, suggesting a greater potency for inducing antibody response (Yang et al., 2009).
Challenge Protocol:
All chickens were challenged with 100EID50 of the IBV SAIBk strain in 0.1 ml by a nasal-ocular route at 21 days after the boost immunization (Yang et al., 2009).
Efficacy:
Immunization with the multivalent DNA vaccine provided up to 85% immune protection in the vaccinated chickens (Yang et al., 2009).
1. Guo et al., 2010: Guo Z, Wang H, Yang T, Wang X, Lu D, Li Y, Zhang Y. Priming with a DNA vaccine and boosting with an inactivated vaccine enhance the immune response against infectious bronchitis virus. Journal of virological methods. 2010; 167(1); 84-89. [PubMed: 20307574].
3. Leyson et al., 2016: Leyson C, França M, Jackwood M, Jordan B. Polymorphisms in the S1 spike glycoprotein of Arkansas-type infectious bronchitis virus (IBV) show differential binding to host tissues and altered antigenicity. Virology. 2016; 498; 218-225. [PubMed: 27619927].
5. Tan et al., 2009: Tan B, Wang H, Shang L, Yang T. Coadministration of chicken GM-CSF with a DNA vaccine expressing infectious bronchitis virus (IBV) S1 glycoprotein enhances the specific immune response and protects against IBV infection. Archives of virology. 2009; 154(7); 1117-1124. [PubMed: 19543689].
7. Yan et al., 2013: Yan F, Zhao Y, Hu Y, Qiu J, Lei W, Ji W, Li X, Wu Q, Shi X, Li Z. Protection of chickens against infectious bronchitis virus with a multivalent DNA vaccine and boosting with an inactivated vaccine. Journal of veterinary science. 2013; 14(1); 53-60. [PubMed: 23388447].
8. Yang et al., 2009: Yang T, Wang HN, Wang X, Tang JN, Gao R, Li J, Guo ZC, Li YL. Multivalent DNA vaccine enhanced protection efficacy against infectious bronchitis virus in chickens. The Journal of veterinary medical science / the Japanese Society of Veterinary Science. 2009; 71(12); 1585-1590. [PubMed: 20046025].
9. Zhang et al., 2014: Zhang J, Chen XW, Tong TZ, Ye Y, Liao M, Fan HY. BacMam virus-based surface display of the infectious bronchitis virus (IBV) S1 glycoprotein confers strong protection against virulent IBV challenge in chickens. Vaccine. 2014; 32(6); 664-670. [PubMed: 24342247].
10. Zhang et al., 2014: Zhang J, Chen XW, Tong TZ, Ye Y, Liao M, Fan HY. BacMam virus-based surface display of the infectious bronchitis virus (IBV) S1 glycoprotein confers strong protection against virulent IBV challenge in chickens. Vaccine. 2014; 32(6); 664-670. [PubMed: 24342247].
