The Negative Impact of Chicken Infectious Anemia Virus Infection on Immune Responses to Different Newcastle Disease Virus Vaccination Programs

Abstract

Chicken infectious anemia virus (CIAV) is among the naturally occurring viruses that cause immunosuppression in chickens. In the present study, the impact of CIAV infection on both NDV vaccination immune responses and bird performance were demonstrated. Post CIAV infection, the mean live body weights of the ND-vaccinated groups showed improvement compared with the non-NDV vaccinated groups. The immunosuppressive effects of CIAV infection was higher and more obvious on live ND vaccinated group compared with the other vaccinated groups. The vaccination with combination of live and inactivated vaccines showed better HI-NDV Ab responses especially when inactivated vaccine was administrated at 9 days (group II). In consistent, both the phagocytic Percent and Index were lower in case of vaccination with live NDV vaccine only and CIAV infection. Birds were vaccinated with both live and inactivated NDV vaccines at different time points showed superior protection rate (100%) compared with the other groups. Microscopically, CIAV infection led to severe deterioration in the lymphoid tissues (thymus, bursa, spleen and bone marrow) such as focal to diffuse depletion of lymphocytes and hematopoietic cells. This study highlights the negative impact of CIAV infection on both bird performance and immune status.

Avian Paramyxovirus Type 1 in Egypt: Epidemiology, Evolutionary Perspective, and Vaccine Approach

“…Upon evaluation, the ND live virus vaccine protected from clinical disease (90%) and deaths (80%) in case of homologous challenge with GII of VG/GA live strain (77) and HB1 with LaSota live strains (156) but only 75% protection rate from clinical disease and deaths as reported by Lebdah et al (157). These protection percentages were raised up to 100% upon inclusion of inactivated vaccines with HB1 and LaSota live vaccines (156,157). However, the results of Mohamed et al (158) were drastic when they used DNA vaccine containing F and HN antigens in one dose (30-40%); then they improved the protection to 90-100% by introducing two or three vaccine doses at 1 week apart.…”

“…Some studies were designated to evaluate different vaccines and/or vaccine regimens applied in Egypt. Upon evaluation, the ND live virus vaccine protected from clinical disease (90%) and deaths (80%) in case of homologous challenge with GII of VG/GA live strain (77) and HB1 with LaSota live strains (156) but only 75% protection rate from clinical disease and deaths as reported by Lebdah et al (157). These protection percentages were raised up to 100% upon inclusion of inactivated vaccines with HB1 and LaSota live vaccines (156,157).…”

“…Other regions, including the fusion peptide ; heptad repeats a, b, and c (HRa 143-185, HRb 268-299, and HRc 471-500); transmembrane (TM) domain (501-522); and cytoplasmic (CT) tail (523-553) were subjected to aa analysis, where several mutations were reported, which might affect the folding and fusion activities of the protein as described in the fusion peptide (87,88) or the HRa, b, and c (89). The HRa is also supposed to include a potential antigenic epitope (90,(149)(150)(151)(152)(153)(154)(155)(156)(157)(158)(159)(160)(161)(162)(163); however, the Egyptian NDV isolates had only few reports of aa substitutions in this epitope (V168I and D170N). The TM domain affects the structural confirmation of the F protein, F-HN protein interaction, and fusion activity (91).…”

Newcastle disease virus-attenuated vaccine LaSota played a key role in the pathogenicity of contaminated exogenous virus

“…Potential risks induced by exogenous virus contamination in attenuated or live vaccines are worthy of attention, but the role that the vaccine plays in such diseases equally needs further research and assessment. Although some reports mentioned interactions between the NDV vaccine and CIAV [ 20 – 22 ], the latter did not cause infection through the use of contaminated vaccines. The contamination dose in attenuated vaccines is extremely low, and oral infection is also not a good way for FAdV and CIAV to invade the chicken.…”