Efficiency of natural oils as alternative adjuvants to mineral oils in inactivated avian influenza vaccine formulation.

1. The effectiveness of inactivated vaccines depends on selecting the suitable adjuvant for vaccine formulation. The potency of vaccines with low antigen content can be improved with the appropriate adjuvant. This could allow production of more doses and lower the production cost.2. This study evaluated the efficiency of vaccines prepared using oil extracted from natural sources including argan oil, almond oil, sesame seed oil, pumpkin oil, cactus oil and black seed oil as alternative adjuvants for improving the protection capacity of inactivated influenza virus vaccine as compared to commonly used mineral oils.3. Each vaccine formulation was evaluated for stability, safety and immunogenicity in chickens, as well as for reducing the viral shedding after challenge infection.4. The cactus, sesame and pumpkin seed oil-based vaccines were found to be potent and successfully induced the production of humoral immunity in vaccinated chickens.

Protective efficacy of a prime-boost protocol using H5-DNA plasmid as prime and inactivated H5N2 vaccine as the booster against the Egyptian avian influenza challenge virus.

In this study, a recombinant DNA plasmid was constructed, encoding for HA1 of a selected Egyptian H5N1 virus (isolated during the 2012 outbreaks). In the immunization and challenge experiments, SPF chickens received 1 or 2 doses of H5-DNA plasmid prime, and boosted with the inactivated H5N2 vaccine. Haemagglutination inhibition (HI) titers, protection levels, and the magnitude of virus shedding were compared to that of the chickens that received either DNA plasmid or inactivated H5N2 vaccine alone. H5N1 virus A/chicken/Egypt/128s/2012 (H5N1) highly pathogenic avian influenza (HPAI) clade 2.2.1/C was used for the challenge. Chickens immunized with 1 or 2 doses of H5-DNA vaccine failed to overcome the challenge with 0% and 10% protection, respectively. Quantitative real-time reverse transcription-PCR revealed virus shedding of 2.2 x 104 PCR copies/ml 3 days post challenge (dpc) in the only surviving bird from the group that received 2 doses of plasmid. However, chickens immunized with 1 or 2 doses of H5-DNA plasmid as prime and inactivated H5N2 vaccine as booster, showed 80% protection after challenge, with a viral shedding of 1.2 x 104 PCR copies/ml (1 dose) and 1.6 x 104 PCR copies/ml (2 doses) 3 dpc. The surviving birds in both groups did not shed the virus at 5 and 7 dpc. In H5N2-vaccinated chickens, protection levels were 70% with relatively high virus shedding (1.8 x 104 PCR copies/ml) 3 dpc. HI titers were protective to the surviving chickens. This study reports the efficacy of H5-DNA plasmid to augment reduction in viral shedding and to provide better protection when applied in a prime-boost program with the inactivated AI vaccine.

Isolation and molecular characterization of Newcastle disease virus genotypes II and VIId in Egypt between 2011 and 2012.

The current study was conducted to isolate and characterize Newcastle disease virus (NDV) from recent outbreaks affecting poultry farms in Egypt between 2011 and 2012. Trachea, spleen, liver, proventriculus and caecal tonsils were collected from clinically infected NDV ten different vaccinated broiler farms in Fayoum, Behira and Giza Provinces. Inoculation of all the collected samples in 10-day-old embryonated chicken specific-pathogen-free eggs resulted in isolation of haemagglutinating agents in three samples. These haemagglutinating agents were confirmed as NDV by real-time reverse transcription polymerase chain reaction (rt RT-PCR) using matrix (M) gene-specific primers. The deduced amino acid sequences of the fusion protein revealed that one isolate possessed the motif (112)RRQKRF(117) at the cleavage site, indicating that this isolate is velogenic genotype, whereas the other two isolates carries the motif (112)GRQGRL(117) indicating they are lentogenic genotype. The phylogenetic analysis revealed that the velogenic genotype isolate clustered with published class II genotype VII sub genotype d NDVs and closely related to Middle East isolates, whereas the other two isolates clustered with published class II genotype II NDVs. The spread of velogenic genotype strain to Egypt via Middle Eastern countries is likely to be the source of infection.

Organisation of the human PAX4 gene and its exclusion as a candidate for the Wolcott-Rallison syndrome.

Neonatal diabetes mellitus is a rare condition, the causes of which are mostly unknown. One well defined though very rare entity is the autosomal recessive Wolcott-Rallison syndrome, in which permanent neonatal diabetes, osteopenia, and epiphyseal dysplasia occur. Only five previous families have been reported, and here we describe the second in which parental consanguinity was present. The proband was born to first cousin parents and died at 2 years from the sequelae of poorly controlled diabetes. To test the hypothesis that mutation of PAX4, required in the mouse for pancreatic islet beta cell development, might cause WRS, the structure of the human PAX4 gene was deduced and DNA from two unrelated WRS patients sequenced. No PAX4 mutation was present, though the entire coding region was sequenced in both patients. It therefore appears unlikely that PAX4 is involved in the aetiology of Wolcott-Rallison syndrome, though it remains a good candidate for other forms of neonatal diabetes mellitus.

Effect of subclinical lead toxicity on the immune response of chickens to Newcastle disease virus vaccine.

The effect of lead acetate (20 and 40 mg kg-1 bodyweight daily) administered via the crop from day old to 56 days of age on the immune response to Newcastle disease virus vaccine (NDVV, La Sota strain) was studied in 354 Lohman chickens. Lead decreased the mitogenic response of peripheral blood lymphocytes (PBL) to phytohaemagglutinin-P (PHA-P) in birds vaccinated with NDVV. It also decreased the weights of the bursa of Fabricius, the thymus glands and the spleen relative to bodyweight. Lead administration decreased the antibody titre to NDVV in the vaccinated groups. The percentage mortality due to a challenge with a virulent velogenic Newcastle disease virus was higher in the lead intoxicated birds.

The effect of salinomycin on the immune response of chicks.

The effect of salinomycin drug on the immune system of chickens was investigated. By using the recommended dose 60 mg/kg feed salinomycin was given as anticoccidial drug continuously for 49 days. There was no noticeable significant effect on the humoral and cell-mediated immune responses to Newcastle Disease Virus (NDV) Vaccine. A drastic immunosuppressive effect was manifested by using a dose of 120 mg/kg and characterized by lowered titers of antibodies to NDV, decrease in the relative weight of lymphoid organs, lowered mitogenic response of peripheral blood lymphocytes (PBL) to phytohaemagglutinin (PHA) with reduction of heterophils percentage, as well as reduced protection rate to intramuscular challenge with the velogenic viscerotropic (VV) strain of NDV.

Application of Corynebacterium cutis lysate as an immune stimulant in cattle.

An ultrasonicated lysate of Corynebacterium cutis (Ultracorn, Virbac, France) was administered to 10-day-old calves, 5-month-old calves, and pregnant dams kept under Egyptian environmental conditions. Ninety-five calves and 50 dams were used in the study. All animals were treated with 2 ml/100 kg body weight of killed C cutis. Its effects on body weight gain and on calf mortality and morbidity were recorded. The results obtained showed that treated calves had greater weight gains, reduced susceptibility to common viral pathogens, and lower mortality. When given simultaneously with rinderpest vaccine, an immunopotentiating or adjuvant effect was seen. Thus, treated calves had higher neutralizing antibody titers to rinderpest as compared with untreated calves. When administered to pregnant cows in the last month of pregnancy, the offspring of these animals had higher birth weight, better weight gain, and reduced morbidity.