Effectiveness of a commercial porcine reproductive and respiratory syndrome virus (PRRSV) subunit vaccine against heterologous PRRSV-1 and PRRSV-2 challenge in late-term pregnant gilts

• Published in: Canadian journal of veterinary research Vol. 83; no. 4; pp. 248 - 254
• Main Authors: Oh, Taehwan, Kim, Hanjin, Park, Kee Hwan, Jeong, Jiwoon, Kang, Ikjae, Yang, Siyeon, Chae, Chanhee
• Format: Journal Article
• Language: English
• Published: Canada Canadian Veterinary Medical Association 01.10.2019
• Subjects: Animals; Female; Porcine Reproductive and Respiratory Syndrome - prevention & control; Porcine respiratory and reproductive syndrome virus - classification; Porcine respiratory and reproductive syndrome virus - immunology; Pregnancy; Pregnancy Complications, Infectious - prevention & control; Pregnancy Complications, Infectious - veterinary; Protein Subunits; Swine; Vaccines, Subunit - immunology; Viral Proteins - immunology; Viral Vaccines - immunology
• ISSN: 0830-9000; 1928-9022

The objective of the present study was to evaluate the efficacy of a commercial porcine reproductive and respiratory syndrome virus (PRRSV) subunit vaccine against heterologous PRRSV-1 and PRRSV-2 challenge in late-term pregnant gilts. Gilts were vaccinated intramuscularly 56 and 35 days antepartum (on days 58 and 79 of gestation) and challenged intranasally 21 days antepartum (on day 93 of gestation) with PRRSV-1 or PRRSV-2. Regardless of the challenge strain's genotype, the vaccinated gilts carried their pregnancies to term and farrowed between days 114 and 115 of gestation. All the unvaccinated gilts aborted, between days 105 and 110 of gestation. The vaccinated gilts had a significantly lower level (P < 0.05) of PRRSV viremia and significantly higher levels (P < 0.05) of virus-neutralizing antibodies and interferon-γ-secreting cells compared with the unvaccinated gilts. The mean number of PRRSV-positive cells per area of fetal tissue examined did not differ significantly between the litters from the vaccinated and unvaccinated gilts. The data presented here indicate that vaccination in late-term pregnancy with PRRSV subunit vaccine is efficacious against reproductive failure due to heterologous PRRSV-1 and PRRSV-2 infection.