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

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no abnormal clinical signs were observed in both groups except for two chicks in the 5XP WS group, where one bird was withdrawn due to a vent prolapse, and another bird died with inconclusive necropsy results.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.

CAvant® WO-60 as an Effective Immunological Adjuvant for Avian Influenza and Newcastle Disease Vaccine

Despite the immunogenicity of vaccines currently used in poultry, several pathogens, including avian influenza virus (AIV) and Newcastle disease virus (NDV), cause enormous economic losses to the global poultry industry. The efficacy of vaccines can be improved by the introduction of effective adjuvants. This study evaluated a novel water-in-oil emulsion adjuvant, CAvant® WO-60, which effectively enhanced both the immunogenicity of conserved influenza antigen sM2HA2 and inactivated whole H9N2 antigen (iH9N2). CAvant® WO-60 induced both humoral and cell-mediated immunity in mice and provided 100% protection from challenge with 10 LD50 of A/Aquatic bird/Korea/W81/2005 (H5N2) and A/Chicken/Korea/116/2004 (H9N2) AIV. Importantly, immunization of chickens with iH9N2 plus inactivated NDV LaSota (iNDV) bivalent inactivated vaccine emulsified in CAvant® WO-60 induced seroprotective levels of antigen-specific antibody responses. Taken together, these results suggested that CAvant® WO-60 is a promising adjuvant for poultry vaccines.

Standardisation of Staff Training to Increase Efficiency

In any industry or organization, personnel training is emphasized with reference to National Regulatory Authorities (NRAs) guidelines and other globally accepted guidelines. In spite of many refresher training programs, the pharmaceutical industry still faces significant variations in individual/ team efficiency and productivity. Individuals/teams given the same task, SOPs, environment and materials continue to produce significantly different results reflecting the possibility of operating on different sets of theoretical and practical information, which may stem from differing trainer, training program or training method. This study focused on using a standardized manual for training two teams A and B involved in vaccine production, as a tool to increase employee efficiency, productivity and quality, at a Livestock vaccine manufacturing company, with an objective to shorten the supply chain of vaccines (starting with Newcastle disease vaccine I-2 strain) to improve product quality, availability and affordability up to rural household level and back yard farmers. Baseline data was collected from four pre-training production batches and compared with data collected from three post-training production batches. The results showed that a tailored standardized training was effective in achieving the same level of efficiency, regardless of how late or soon the member joined the facility, and who conducted the training. The process of training staff, using a company tailored standardized manual, was shown to be successful within this company’s set up and could potentially be applied to other industries that are struggling with implementation of uniform information to their staff.

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

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.

Evaluation of Mucosal Immunity in Chickens Vaccinated With Oral Pellet Newcastle Disease Vaccine

The Newcastle disease outbreak in chickens is a continuing threat to the poultry industry. Infection with Newcastle disease is greatly influenced by the immune status of the birds. The mucosal immunity plays a major role in the local immune response in the protection of chickens against diseases. This study was undertaken to find the efficacy of thermostable live oral pellet vaccine in developing the mucosal immunity in chickens. Samples were collected from Harderian gland, Lachrymal fluid, Tracheal fluid, Intestinal washings, Bile and Serum of chickens after administration of oral pellet vaccine to detect presence of NDV specific IgA antibodies. Results showed that there is significant increase in the immune response after one week post vaccination with no significant difference between 14 and 21 days after vaccine. There exists significant difference in Mean OD values between samples of Harderian, Lachrymal, Trachea, Intestine, Bile and serum with bile found to have increased IgA response. Challenge experiment results showed that oral pellet vaccine was able to protect chickens against virus challenge by increasing the mucosal immunity against Newcastle disease.

Response of Laying Hens to Aqueous Extracts of Petiveria alliacea Root and Leaf

This study investigated the response of laying hens to aqueous extracts of Petiveria alliacea root and leaf. A total of 288 eighteen-week-old Isa brown pullets were used for the 25-week study. The pullets were arranged in a 2 × 4 factorial experimental layout in a completely randomized design. The pullets were distributed into two groups administered root extract or leaf extract. Pullets in each group were allotted to four subgroups administered aqueous extracts of Petiveria alliacea at 15, 30 and 45 g l–1 concentration levels making eight treatments in total. Each treatment was replicated three times with twelve pullets per replicate. Eimeria oocyst counts and intestinal bacteria counts were lower (P < 0.0001 and P = 0.0028, respectively) in hens administered 15, 30 and 45 g l–1 of Petiveria alliacea extracts than the control. The highest (P < 0.0001) antibody titre against Newcastle disease vaccine was recorded in hens administered 30 and 45 g l–1 concentrations of root (9.06 and 9.10 log2, respectively) and leaf (9.08 and 9.18 log2, respectively) extracts. The liver sections of hens in all treatments appeared normal. In conclusion, aqueous extract of Petiveria alliacea root and leaf at 30 and 45 g l–1 concentrations performed best as antimicrobial and immune stimulating agent without impairing liver health.

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

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.