title: The effect of parameter selection in evaluation of infectious bronchitis virus vaccine. II. Effect of single vs. serial passage of tracheal swab material, and of the positive-negative vs. a point-value system in reporting results.
mesh_terms: D000818:Animals; D001991:Bronchitis / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary*; D002645:Chickens; D004531:Eggs; D008722:Methods; D011201:Poultry Diseases / Q000276:immunology / Q000517:prevention & control*; D012328:RNA Viruses / Q000276:immunology* / Q000302:isolation & purification; D013997:Time Factors; D014132:Trachea / Q000382:microbiology*; D014765:Viral Vaccines; D014776:Virus Cultivation
chemical_list: D014765:Viral Vaccines