Efficacy of Fostera® PRRS modified live virus (MLV) vaccination strategy against a Thai highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) infection

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• 作者：Ponlakrit Charoenchanikran ; Roongtham Kedkovid…
• 关键词：Efficacy ; HP ; PRRSV ; Lineage 8 ; MLV ; Vaccine
• 刊名：Tropical Animal Health and Production
• 出版年：2016
• 出版时间：October 2016
• 年：2016
• 卷：48
• 期：7
• 页码：1351-1359
• 全文大小：779 KB
• 刊物类别：Medicine
• 刊物主题：Medicine & Public Health
  Veterinary medicine
  Zoology
  
• 出版者：Springer Netherlands
• ISSN：1573-7438
• 卷排序：48

文摘

Recently, the Chinese highly pathogenic porcine reproductive and respiratory syndrome virus (PRRSV) (HP-PRRSV) belonging to lineage 8 causes severe symptom with high morbidity and high mortality rates to the Asian pig industry. A recent study showed that pigs immunized with Fostera® PRRS modified live virus (MLV) of lineage 8 could provide a degree of protection against a Vietnamese HP-PRRSV infection. It should be noted that PRRSV commonly found after weaning causes porcine respiratory disease complex (PRDC). Vaccination strategy should be evaluated in each farm scenario. Eighty-one PRRSV-free piglets obtained from a PRRS-free herd were divided into two experiments with the major difference of infection timing after vaccination, 42 days in experiment 1 (n = 42) and 28 days in experiment 2 (n = 39). Each experiment had similar protocol containing three groups including a negative control, unvaccinated challenged, and vaccinated challenged groups. Pigs in vaccination groups were immunized with Fostera® PRRS MLV vaccine at 3 weeks of age. Then, unvaccinated challenged and vaccinated challenged groups were intranasally inoculated with a Thai HP-PRRSV (10PL01). Vaccinated challenged pigs showed significantly lower levels of mean rectal temperatures, clinical severity, lung lesion scores, and viral titers in serum and lung tissue compared to the unvaccinated challenged pigs (p < 0.05). Vaccinated challenged pigs had higher survival rate than those of unvaccinated challenged pigs in both experiments. It should be noted that pigs challenged 42 days after vaccination showed a better performance than pigs challenged 28 days after vaccination. In conclusion, Fostera® PRRS MLV vaccine was able to improve the survival rate against the Thai HP-PRRSV infection in both 42- and 28-day vaccination-to-infection protocols.