title: Emergency vaccination alleviates highly pathogenic porcine reproductive and respiratory syndrome virus infection after contact exposure.
abstract: BACKGROUND
  To assess the effectiveness of emergency vaccination for reducing the contact-induced infection and pathological damage caused by the highly pathogenic porcine reproductive and respiratory syndrome virus (HPPRRSV), Twenty pigs were equally divided into four groups. Groups 1, 2 and 3 were housed in one unit, whereas Group 4 was separately housed. Group 1 was challenged with HPPRRSV on day 0. Group 2 and 4 did not receive treatment and were used as the contact-infected and uninfected controls, respectively. Group 3 was treated with the attenuated vaccine at 0 days post-inoculation. The rectal temperatures, clinical signs, pathologic lesions and viraemia of the piglets were detected and evaluated.
  
  
  RESULTS
  The vaccinated pigs in Group 3 showed less clinical morbidity, viraemia, temperature fluctuations and lung lesions at 14 days post-inoculation, as compared with the contact-infected (Group 2) and experimentally infected (Group 1) pigs. Higher serum IFN-γ levels were detected among the pigs that received emergency immunisation. Thus, IFN-γ may be involved in immunity against HPPRRSV infection.
  
  
  CONCLUSIONS
  These results indicated that emergency vaccination could effectively alleviate HPPRRSV infection during experimental contact exposure. Our findings provide a novel and useful strategy for controlling clinical HPPRRSV.
authors: College of Veterinary Medicine, Northwest A&F University, Yangling 712100, China.
authors: Xiao
authors: X
authors: Li
authors: Li
authors: L
authors: Qiu
authors: Zengqi
authors: Z
authors: Yang
authors: Ruiyi
authors: R
authors: Dang
authors: Xinglong
authors: X
authors: Wang
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood / Q000276:immunology; D004630:Emergencies / Q000662:veterinary; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D006799:Housing, Animal; D007371:Interferon-gamma / Q000097:blood; D019318:Porcine Reproductive and Respiratory Syndrome / Q000276:immunology / Q000517:prevention & control*; D019316:Porcine respiratory and reproductive syndrome virus / Q000276:immunology*; D013552:Swine / Q000276:immunology / Q000821:virology; D014765:Viral Vaccines / Q000008:administration & dosage / Q000276:immunology / Q000627:therapeutic use*; D014766:Viremia / Q000662:veterinary / Q000821:virology
chemical_list: D000914:Antibodies, Viral; D014765:Viral Vaccines; D007371:Interferon-gamma
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