scholarly journals Newcastle disease vaccine virus I-2 fails to acquire virulence during repeated passage in vivo

2021 ◽  
Vol 5 ◽  
pp. 76
Author(s):  
Shahn P.R. Bisschop ◽  
Andrew Peters ◽  
Gil Domingue ◽  
Michael C. Pearce ◽  
Jeanette Verwey ◽  
...  
Keyword(s):  
Newcastle Disease ◽  
Clinical Signs ◽  
Vaccine Virus ◽  
Amino Acid Sequences ◽  
Tissue Homogenates ◽  
Tracheal Tissue ◽  
Repeated Passage ◽  
Low Passage ◽  
Newcastle Disease Vaccine

Background This study determined whether the naturally attenuated, thermotolerant Newcastle disease vaccine virus I-2 could acquire virulence after five in vivo passages through SPF chickens. Methods Study design was to international requirements including European Pharmacopoeia, Ph. Eur., v9.0 04/2013:0450, 2013. I-2 Working Seed (WS) was compared with five-times-passaged I-2 WS (5XP WS) in intracerebral pathogenicity index (ICPI), Fo cleavage site sequencing and Safety tests. Results The first passage series used a 50% brain: 50% tracheal tissue challenge homogenate and was unsuccessful as I-2 was not detected after the fourth passage. A second passage series used 10% brain: 90% tracheal tissue homogenates. I-2 was isolated from tracheal tissue in each passage. However harvested titres were below the minimum challenge level (107 EID50) specified for the ICPI and Safety tests, possibly reflecting I-2’s inherently low pathogenicity (interestingly caecal tonsils yielded significant titres). Given this the WS and 5XP WS comparisons proceeded. ICPI values were 0.104 and 0.073 for the WS group and the 5XP WS group respectively confirming that I-2, whether passaged or not, expressed low pathogenicity. F0 amino-acid sequences for both WS and 5XP WS were identified as 112R-K-Q-G-R-↓-L-I-G119 and so compatible with those of avirulent ND viruses. In safety, no abnormal clinical signs were observed in both groups except for two chicks in the 5XP WS group, where one bird was withdrawn due to a vent prolapse, and another bird died with inconclusive necropsy results. Conclusions: These data, the issue of low passage titres with little or no virus isolation from brain tissues and the genomic copy approach suggest a need to amend Ph. Eur. v9.0 04/2013:0450, 2013 for naturally attenuated, low pathogenicity vaccine viruses such as I-2. From an international regulatory perspective, the study provides further definitive data demonstrating that Newcastle disease vaccine virus I-2 is safe for use.

scholarly journals Newcastle disease vaccine virus I-2 fails to acquire virulence during repeated passage in vivo

2021 ◽  
Vol 5 ◽  
pp. 76
Author(s):  
Shahn P.R. Bisschop ◽  
Andrew Peters ◽  
Gil Domingue ◽  
Michael C. Pearce ◽  
Jeanette Verwey ◽  
...  
Keyword(s):  
Newcastle Disease ◽  
Clinical Signs ◽  
Vaccine Virus ◽  
Amino Acid Sequences ◽  
Tissue Homogenates ◽  
Tracheal Tissue ◽  
Repeated Passage ◽  
Low Passage ◽  
Newcastle Disease Vaccine

Background This study determined whether the naturally attenuated, thermotolerant Newcastle disease vaccine virus I-2 could acquire virulence after five in vivo passages through SPF chickens. Methods Study design was to international requirements including European Pharmacopoeia, Ph. Eur., v9.0 04/2013:0450, 2013. I-2 Working Seed (WS) was compared with five-times-passaged I-2 WS (5XP WS) in intracerebral pathogenicity index (ICPI), Fo cleavage site sequencing and Safety tests. Results The first passage series used a 50% brain: 50% tracheal tissue challenge homogenate and was unsuccessful as I-2 was not detected after the fourth passage. A second passage series used 10% brain: 90% tracheal tissue homogenates. I-2 was isolated from tracheal tissue in each passage. However harvested titres were below the minimum challenge level (107 EID50) specified for the ICPI and Safety tests, possibly reflecting I-2’s inherently low pathogenicity (interestingly caecal tonsils yielded significant titres). Given this the WS and 5XP WS comparisons proceeded. ICPI values were 0.104 and 0.073 for the WS group and the 5XP WS group respectively confirming that I-2, whether passaged or not, expressed low pathogenicity. F0 amino-acid sequences for both WS and 5XP WS were identified as 112R-K-Q-G-R-↓-L-I-G119 and so compatible with those of avirulent ND viruses. In safety, no abnormal clinical signs were observed in both groups except for two chicks in the 5XP WS group, where one bird was withdrawn due to a vent prolapse, and another bird died with inconclusive necropsy results. Conclusions: These data, the issue of low passage titres with little or no virus isolation from brain tissues and the genomic copy approach suggest a need to amend Ph. Eur. v9.0 04/2013:0450, 2013 for naturally attenuated, low pathogenicity vaccine viruses such as I-2. From an international regulatory perspective, the study provides further definitive data demonstrating that Newcastle disease vaccine virus I-2 is safe for use.

scholarly journals Newcastle disease vaccine virus I-2 fails to acquire virulence during repeated passage in vivo

2021 ◽  
Vol 5 ◽  
pp. 76
Author(s):  
Shahn P.R. Bisschop ◽  
Andrew Peters ◽  
Gil Domingue ◽  
Michael C. Pearce ◽  
Jeanette Verwey ◽  
...  
Keyword(s):  
Newcastle Disease ◽  
Clinical Signs ◽  
Vaccine Virus ◽  
Amino Acid Sequences ◽  
Tissue Homogenates ◽  
Tracheal Tissue ◽  
Repeated Passage ◽  
Low Passage ◽  
Newcastle Disease Vaccine

Background This study determined whether the naturally attenuated, thermotolerant Newcastle disease vaccine virus I-2 could acquire virulence after five in vivo passages through SPF chickens. Methods Study design was to international requirements including European Pharmacopoeia, Ph. Eur., v9.0 04/2013:0450, 2013. I-2 Working Seed (WS) was compared with five-times-passaged I-2 WS (5XP WS) in intracerebral pathogenicity index (ICPI), Fo cleavage site sequencing and Safety tests. Results The first passage series used a 50% brain: 50% tracheal tissue challenge homogenate and was unsuccessful as I-2 was not detected after the fourth passage. A second passage series used 10% brain: 90% tracheal tissue homogenates. I-2 was isolated from tracheal tissue in each passage. However harvested titres were below the minimum challenge level (107 EID50) specified for the ICPI and Safety tests, possibly reflecting I-2’s inherently low pathogenicity (interestingly caecal tonsils yielded significant titres). Given this the WS and 5XP WS comparisons proceeded. ICPI values were 0.104 and 0.073 for the WS group and the 5XP WS group respectively confirming that I-2, whether passaged or not, expressed low pathogenicity. F0 amino-acid sequences for both WS and 5XP WS were identified as 112R-K-Q-G-R-↓-L-I-G119 and so compatible with those of avirulent ND viruses. In safety, no abnormal clinical signs were observed in both groups except for two chicks in the 5XP WS group, where one bird was withdrawn due to a vent prolapse, and another bird died with inconclusive necropsy results. Conclusions: These data, the issue of low passage titres with little or no virus isolation from brain tissues and the genomic copy approach suggest a need to amend Ph. Eur. v9.0 04/2013:0450, 2013 for naturally attenuated, low pathogenicity vaccine viruses such as I-2. These results add to the literature and field data demonstrating that Newcastle Disease vaccine virus I-2 is safe for use.

Experimental Infection and Transmission of Newcastle Disease Vaccine Virus in Four Wild Passerines

2019 ◽  
Vol 63 (3) ◽  
pp. 389
Author(s):  
Andrea J. Ayala ◽  
Sonia M. Hernandez ◽  
Timothy L. Olivier ◽  
Catharine N. Welch ◽  
Kiril M. Dimitrov ◽  
...  
Keyword(s):  
Experimental Infection ◽  
Newcastle Disease ◽  
Vaccine Virus ◽  
Newcastle Disease Vaccine

scholarly journals Molecular Characterization of Small Ruminant Lentiviruses of Subtype A5 Detected in Naturally Infected but Clinically Healthy Goats of Carpathian Breed

Pathogens ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 992
Author(s):  
Monika Olech ◽  
Jacek Kuźmak
Keyword(s):  
Small Ruminant ◽  
Clinical Signs ◽  
Small Ruminants ◽  
Pairwise Comparison ◽  
Biological Properties ◽  
Amino Acid Sequences ◽  
Surface Glycoprotein ◽  
Pathogenic Potential ◽  
Small Ruminant Lentiviruses

Small ruminant lentiviruses (SRLVs) are widespread in sheep and goats in Poland, and several subtypes were identified and molecularly characterized up to date. This is the first study that characterizes the molecular properties of A5 strains of SRLV detected in naturally infected, but clinically healthy, Carpathian goats. Segments from three genomic regions (gag, env, and LTR) were analyzed. Genetic distance, pairwise comparison, and phylogenetic analysis revealed that Polish SRLV A5 sequences are closely related to the Swiss and German A5 sequences suggesting a common origin. The epidemiological linkage was identified particularly between the small ruminants of Germany and Poland. Amino acid sequences of immunodominant regions in CA protein were well-conserved within analyzed strains; however, they showed some remarkable changes like substitution (D) to (E), at position 90 in Major Homology Region (MHR) and (T) to (S), at position 141 in epitope 3. In contrast, aa sequences of surface glycoprotein exhibited the highest variability confirming type-specific variation in SU5 epitope. Two deletions in the U3 region of A5 strains were noted: One (8 nt) located near the 5′ end of the U3 region and the other (29 nt) located in the central region of U3. Additionally, all A5 strains had specific deletion (10 nt) in the R region. Furthermore, we did not find a correlation between copies of the CAAAT motif and clinical manifestation in infected animals. These data showed some remarkable features in the viral genome of A5 strains, which may be related to the attenuated phenotype in vivo, characterized by the lack of any clinical signs in infected goats. Certainly, more studies are required to support the hypothesis that these A5 viruses are of low pathogenicity for goats. We want to focus our future studies on the analysis of the whole genomes of these isolates and their biological properties, as well as on clinicopathological studies of goats infected by A5 SRLV, aiming to clarify the pathogenic potential of these viruses.

scholarly journals Spray drying of an attenuated live Newcastle disease vaccine virus intended for respiratory mass vaccination of poultry

Vaccine ◽  
2007 ◽  
Vol 25 (49) ◽  
pp. 8306-8317 ◽  
Author(s):  
E.A. Corbanie ◽  
J.P. Remon ◽  
K. Van Reeth ◽  
W.J.M. Landman ◽  
J.H.H. van Eck ◽  
...  
Keyword(s):  
Spray Drying ◽  
Newcastle Disease ◽  
Vaccine Virus ◽  
Mass Vaccination ◽  
Newcastle Disease Vaccine
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