Long term protection against a virulent field isolate of Infectious laryngotracheitis virus induced by inactivated, recombinant, and modified live virus vaccines in commercial layers.

The objective of this study was to assess the protection efficacy against ILT induced by recombinants; live-modified attenuated; and inactivated virus vaccines when administered alone or in combination. Commercial layer pullets were vaccinated with one or more vaccines and challenged at 35 (35WCH) or 74 weeks of age (74WCH). Protection was assessed by scoring clinical signs; and by determining the challenge viral load in the trachea at five days post-challenge. The FPV-LT vaccinated birds were not protected when challenged at 35WCH; the HVT-LT and TCO vaccines in combination provided protection similar to that observed in chickens vaccinated with either HVT-LT or TCO vaccines when challenged at 35WCH, whereas protection induced by vaccination with HVT-LT followed by TCO was superior at 74WCH than at 35WCH. Birds given the inactivated ILT vaccine had fewer clinical signs and/or viral replication at 74WCH when combined with TCO or HVT-LT, but not when given alone. Finally, the CEO-vaccinated birds had top protection as indicated by reduction of clinical signs and viral replication when challenged at 35WCH (74WCH not done). These results suggest that certain vaccine combinations may be successful to produce long-term protection up to 74 weeks of age against ILT. PMID: 30640536 [PubMed - as supplied by publisher]
Source: Avian Pathology - Category: Pathology Authors: Tags: Avian Pathol Source Type: research

Related Links:

th The poultry industry currently accounts for the production of around 118 million metric tons of meat and around 74 million metric tons of eggs annually. As the global population continues to increase, so does our reliance on poultry as a food source. It is therefore of vital importance that we safeguard this valuable resource and make the industry as economically competitive as possible. Avian viral infections, however, continue to cost the poultry industry billions of dollars annually. This can be in terms of vaccination costs, loss of birds and decreased production. With a view to improving the health and welfare ...
Source: Genes - Category: Genetics & Stem Cells Authors: Tags: Editorial Source Type: research
AbstractVeterinary vaccines need to have desired characteristics, such  as being effective, inexpensive, easy to administer, suitable for mass vaccination and stable under field conditions. DNA vaccines have been proposed as potential solutions for poultry diseases since they are subunit vaccines with no risk of infection or reversion to virulence. DNA vaccines can be utilized for simultaneous immunizations against multiple pathogens and are relatively easy to design and inexpensive to manufacture and store. Administration of DNA vaccines has been shown to stimulate immune responses and provide protection from challen...
Source: Veterinary Research - Category: Veterinary Research Source Type: research
Abstract Influenza viruses remain a severe burden to human health because of their contribution to overall morbidity and mortality. Current seasonal influenza virus vaccines do not provide sufficient protection to alleviate the annual impact of influenza and cannot confer protection against potentially pandemic influenza viruses. The lack of protection is due to rapid changes of the viral epitopes targeted by the vaccine and the often suboptimal immunogenicity of current immunization strategies. Major efforts to improve vaccination approaches are under way. The development of a universal influenza virus vaccine ma...
Source: Annual Review of Medicine - Category: General Medicine Authors: Tags: Annu Rev Med Source Type: research
This study reports on the simultaneous administration of live NDV or aMPV subtype B vaccines alongside two live IBV (Massachusetts-H120 and 793B-CR88) vaccines in day-old maternal-antibody positive commercial broiler chicks. In the first experiment, chicks were divided into four groups; one unvaccinated and three groups vaccinated with live NDV VG/GA-Avinew, live H120 + CR88, or VG/GA-Avinew + H120 + CR88. In the second experiment, live aMPV subtype B vaccine was used in place of NDV. Clinical signs were monitored daily and oropharyngeal swabs were taken at regular intervals for vaccine virus detection. Blood w...
Source: Vaccine - Category: Allergy & Immunology Authors: Tags: Vaccine Source Type: research
Publication date: Available online 8 October 2019Source: Microbial PathogenesisAuthor(s): Momena Habib, Tahir Yaqub, Aziz-ul-Rahman, Tayyebah Sohail, Muhammad Shahbaz, Wasim Shehzad, Muhammad Munir, Muhammad Zubair ShabbirAbstractNewcastle disease (ND), caused by Avian orthoavulavirus 1 (AOAV-1), affects multiple avian species around the globe. Frequent disease outbreaks are not uncommon even in vaccinates despite routine vaccination and, in this regards, viruses of diverse genotypes originating from natural reservoirs (migratory waterfowls) play an important role in a disease endemic setting. Though genomic characterizati...
Source: Microbial Pathogenesis - Category: Infectious Diseases Source Type: research
In this study, we investigated the delivery of insect cell culture-derived recombinant hemagglutinin protein (HA) of A/H5N1/Vietnam/1203/2004 virus using CaPNP. We evaluated the vaccine immunogenicity in mice following two intramuscular doses of 3 μg antigen combined with escalating doses of CaPNP. Our data showed CaPNP-adjuvanted HA(H5N1) vaccines eliciting significantly higher IgG, hemagglutination inhibition, and virus neutralization titers compared to non-adjuvanted vaccine. Among the four adjuvant doses that were tested, CaPNP at 0.24% final concentration elicited the highest IgG and neutralizing antibody tite...
Source: AAPS PharmSciTech - Category: Drugs & Pharmacology Authors: Tags: AAPS PharmSciTech Source Type: research
The objective of this theoretical study was to elucidate how these behavioral adaptations may affect the epidemiology of highly-pathogenic avian influenza in domestic poultry and the outcome of the implemented control policies. We studied a symmetric population game where the players are broiler poultry farmers at risk of infection and where the between-farms disease transmission is both environmental and mediated by poultry trade. Three types of farmer behaviors were modelled: vaccination, depopulation, and cessation of poultry farming. We found that the transmission level of the disease through trade networks has strong ...
Source: Epidemics - Category: Epidemiology Source Type: research
CONCLUSION: Although the concept of mandatory vaccination seems to be favoured by many health professionals in Europe, it remains a controversial subject both among HCWs' profession categories and also among different countries. Interventions to increase vaccination among HCWs would benefit by tailoring their approach according to disease and target group. PMID: 31580555 [PubMed - in process]
Source: Central European Journal of Public Health - Category: International Medicine & Public Health Tags: Cent Eur J Public Health Source Type: research
In this study, a novel oral vaccine of recombinant Lactobacillus plantarum (L. plantarum) containing the gp85 protein was explored, and the effects of this vaccine on the prevention of subgroup J Avian Leukosis Virus (ALV-J) infection were assessed. In the current study, the gp85 protein of ALV-J was expressed on the surface of L. plantarum with the surface-display motif, pgsA, by constructing a shuttle vector pMG36e:pgsA:gp85. Surface localization of the fusion protein was verified by western blotting and flow cytometry. Subsequently, Specific Pathogen Free Hy-Line Brown layer chickens were orally vaccinated with the reco...
Source: Frontiers in Immunology - Category: Allergy & Immunology Source Type: research
In conclusion, the IBVs circulating in southern China over the past decade have experienced a remarkable change in genetic diversity, dominant genotypes, and selection pressure, indicating the importance of permanent monitoring of circulating strains and the urgency for developing new vaccines to counteract the emerging LX4-type and New-type IBVs.
Source: Viruses - Category: Virology Authors: Tags: Article Source Type: research
More News: Bird Flu | Middle East Health | Pathology | Respiratory Medicine | Study | Turkey Health | Vaccines