To determine the genetic and epidemiological relationship of infectious bronchitis virus (IBV) isolates from commercial poultry to attenuated live IBV vaccines we conducted a phylogenetic network analysis on the full-length S1 sequence for Arkansas (Ark), Massachusetts (Mass) and Delmarva/1639 (DMV/1639) type viruses isolated in 2015 from clinical cases by 3 different diagnostic laboratories. P...

Newcastle disease virus (NDV) can cause severe disease in chickens. Although NDV vaccines exist, there are frequent reports of outbreaks in vaccinated chickens. During 2009-2010, despite intense vaccination, NDV caused major outbreaks among commercial poultry farms in Indonesia. These outbreaks raised concern regarding the protective immunity of current vaccines against circulating virulent str...

Background: Newcastle disease virus (NDV) genotype VII has become the dominant genotype in China. However, NDV genotype II was used to make current commercial NDV vaccines. The mismatch of genotypes between circulating and vaccine strains of viruses may compromise the efficacy of vaccines. Methods: In this study, a current circulating NDV was attenuated by mutations of multiple basic amino acid...

this experiment was conducted for evaluating the humoral immune responses induced by poly lactide-co-glycolide acid (plga) microspheres coupled inactivated newcastle disease virus (ndv) vaccine in comparison to an ‘in-house’ prepared inactivated and a live commercial vaccine. plg microparticles containing inactivated ndv were prepared by a double emulsion technique based on solvent evaporation ...

Background: Major histocompatibility complex (MHC) is one of the best characterized genetic regions controlling immune responses against vaccines. Identifying the association between MHC haplotypes and improved immune responses would be useful in genetic breeding strategies in animals. OBJECTIVES: MHC class II B genetic diversity and its association with humoral immune responses against Newcast...

In the United States, more than 90% of chicken meat is produced in the southeastern states, and most egg production resides in the eastern half of the country and Texas. Several molecular epidemiological studies have indicated that most infectious bronchitis (IB) virus (IBV) isolates obtained from outbreaks of respiratory disease in these regions correspond to Ark-type IBV in spite of extensive...

Newcastle disease virus (NDV) is the causative agent of an economically important disease, which affects all species of birds worldwide. Current vaccination programs for NDV include the use of either low-virulent live-virus vaccines or inactivated vaccines to induce protective immunity while producing minimal adverse effects in birds. In order to further characterize the immune response elicite...

Avian infectious bronchitis virus (IBV) causes tremendous economic losses to the poultry industry worldwide. Different serotypes of this virus show little cross-protection. The present study investigated the relationship between differences in the genotype based on the N-terminus of the spike protein and the protection provided by vaccination with IBVs. Cross-immunization tests were performed u...

Newcastle disease (ND) is one of the most serious illnesses of chickens. Live vaccines are widely used to prevent chicken from the disease all over the world. To access the effective and potentiate ND vaccine, a homogenous subpopulation from LaSota strain was selected following cultivation of the virus on primary chicken embryofibroblast (CEF) cells. Pathogenicity indices and molecular characte...

This experiment was conducted for evaluating the humoral immune responses induced by Poly Lactide-co-Glycolide Acid (PLGA) microspheres coupled inactivated Newcastle Disease Virus (NDV) vaccine in comparison to an ‘in-house’ prepared inactivated and a live commercial vaccine. PLG microparticles containing inactivated NDV were prepared by a double emulsion technique based on solvent evaporation ...