Commercial vaccines provide limited protection to NADC30-like PRRSV infection. Issue 46 (4th November 2016)

• Record Type: Journal Article
• Authors: Bai, Xiaofei; Wang, Yuzhou; Xu, Xin; Sun, Zhe; Xiao, Yan; Ji, Guobiao; Li, Yingying; Tan, Feifei; Li, Xiangdong; Tian, Kegong
• Is Part Of: Vaccine. Volume 34:Issue 46(2016)
• Page Start: 5540
• Page End: 5545
• Publication Date: 2016-11-04
• Subjects: NADC30-like PRRSV -- Commercial PRRSV vaccines -- Vaccine efficacy; Vaccines -- Periodicals; 615.372
• DOI: 10.1016/j.vaccine.2016.09.048
• Languages: English
• ISSNs: 0264-410X

Abstract

Highlights: Five PRRSV vaccines have been tested for the efficacy to NADC30-like PRRSV challenge. Vaccinated pigs had improved clinical manifestations compared to unvaccinated ones. However, vaccinated pigs developed similar viremia and suffered pathological lesions. PRRSV vaccines could not provide complete protection to NADC30-like PRRSV infection. Abstract: NADC30-like PRRSV has been recently reported and became endemic in vaccinated pig herds in China. The outbreaks of disease in vaccinated pigs indicated the inefficacy of commercial PRRSV vaccines. In this study, five commercial PRRSV vaccines that have been widely used in China were used to evaluate the efficacy to a NADC30-like PRRSV infection. The vaccinated pigs were challenged with HNjz15, a NADC30-like PRRSV at 28 days post vaccination. Compared to unvaccinated pigs, the vaccinated pigs clinically shortened the period of fever with less pig numbers of clinical manifestations and had improved body weight gain at the end of the study. However, the vaccinated pigs developed viremia with similar kinetics and suffered pathological lesions in lung and lymphoid tissues as the unvaccinated pigs. The virus load in tonsil, lung and lymph nodes detected by immunohistochemistry staining in vaccinated pigs was also similar to that in unvaccinated pigs which indicated the inability of vaccination to eradicate the virus from tissues of vaccinated pigs. Therefore, the above results suggested current commercial PRRSV vaccines could not provide complete protection to the NADC30-like PRRSV infection.