The required sample size in vaccination-challenge experiments with infectious bronchitis virus, a meta-analysis.

The required sample size in vaccination-challenge experiments with infectious bronchitis virus, a meta-analysis. Avian Pathol. 2013 Feb;42(1):9-16 Authors: de Wit JJ, Boelm GJ, van Gerwe TJ, Swart WA Abstract For statistical, animal welfare and financial reasons the choice of the number of chickens per group in experiments is important. This estimation, together with the number of tracheal organ cultures (TOCs) that need to be examined from each chicken in order to assess protection, should be based on the difference in level of protection that one would like to be able to detect (effect size), the expected variability of the results between and within the chickens, the desired confidence level and the power of the study. To obtain data that would facilitate this estimation, a meta-analysis was performed on the data from 18 infectious bronchitis virus (IBV) vaccination-challenge experiments performed at the Dutch Animal Health Service Deventer, the Netherlands (GD) in order to determine and quantify the source of variation in the mean level of protection of different groups. For the calculations, 137 groups of chickens were subdivided into 10 clusters based on age (young or adult), vaccination (none, homologous or heterologous), challenge (IBV or mock infected) and location of vaccination (isolator at GD or in the field). The results were used to estimate the required number of chickens per group for the different clusters using 2, 5 or 10 TOCs per chicken to...
Source: Avian Pathology - Category: Pathology Authors: Tags: Avian Pathol Source Type: research

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AbstractDespite the fact that vaccine resistance has been typically considered a rare phenomenon, some episodes of vaccine failure have been reported with increasing frequency in intensively-raised livestock. Infectious bronchitis virus (IBV) is a widespread avian coronavirus, whose control relies mainly on extensive vaccine administration. Unfortunately, the continuous emergence of new vaccine-immunity escaping variants prompts the development of new vaccines. In the present work, a molecular epidemiology study was performed to evaluate the potential role of homologous vaccination in driving IBV evolution. This was undert...
Source: Veterinary Research - Category: Veterinary Research Source Type: research
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Source: Avian Pathology - Category: Pathology Authors: Tags: Avian Pathol Source Type: research
Reena Goswami1, Gayatri Subramanian2, Liliya Silayeva1, Isabelle Newkirk1, Deborah Doctor1, Karan Chawla2, Saurabh Chattopadhyay2, Dhyan Chandra3, Nageswararao Chilukuri1 and Venkaiah Betapudi1,4* 1Neuroscience Branch, Research Division, United States Army Medical Research Institute of Chemical Defense, Aberdeen, MD, United States 2Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, United States 3Roswell Park Comprehensive Cancer Center, Buffalo, NY, United States 4Department of Physiology and Biophysics, Case Western Reserve University, Clev...
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Source: Tropical Animal Health and Production - Category: Veterinary Research Source Type: research
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Source: Tropical Animal Health and Production - Category: Veterinary Research Source Type: research
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Source: Veterinary Microbiology - Category: Veterinary Research Source Type: research
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Source: Veterinary Research - Category: Veterinary Research Source Type: research
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Source: Research in Veterinary Science - Category: Veterinary Research Source Type: research
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Source: Veterinary Microbiology - Category: Veterinary Research Source Type: research
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Source: Veterinary Microbiology - Category: Veterinary Research Source Type: research
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