scholarly journals Evaluation of the Efficacy of an Attenuated Live Vaccine against Highly Pathogenic Porcine Reproductive and Respiratory Syndrome Virus in Young Pigs

2012 ◽  
Vol 19 (8) ◽  
pp. 1199-1206 ◽  
Author(s):  
Xue Leng ◽  
Zhenguang Li ◽  
Mingqi Xia ◽  
Yanliang He ◽  
Hua Wu
Keyword(s):  
Respiratory Syndrome Virus ◽  
Effective Protection ◽  
Lethal Challenge ◽  
Highly Pathogenic ◽  
Live Virus ◽  
Pork Industry ◽  
Live Virus Vaccine ◽  
Young Pigs ◽  
Prrsv Strain

ABSTRACTHighly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) is characterized by high fever and high mortality in pigs of all ages and has severely affected the pork industry of China in the last few years. An attenuated HP-PRRSV strain, TJM, was obtained by passaging HP-PRRSV strain TJ on MARC-145 cells for 92 passages. Porcine reproductive and respiratory syndrome virus (PRRSV)- and antibody-free pigs were inoculated intramuscularly with TJM (105.050% tissue culture infective doses [TCID50]) and challenged at 28, 60, 120, and 180 days postimmunization (dpi). The results showed that 5/5, 5/5, 5/5, and 4/5 immunized pigs were protected from the lethal challenge and did not develop fever and clinical diseases at each challenge, respectively. Compared to control pigs, vaccinated pigs showed much milder pathological lesions and gained significantly more weight (P< 0.01). Sequence analysis of different passages of strain TJ showed that the attenuation resulted in a deletion of a continuous 120 amino acids (aa), in addition to the discontinuous 30-aa deletion in the nsp2 region. The analysis also demonstrated that the 120-aa deletion was genetically stablein vivo. These results suggested that HP-PRRSV TJM was efficacious against a lethal challenge with a virulent HP-PRRSV strain, and effective protection could last at least 4 months. Therefore, strain TJM is a good candidate for an efficacious modified live virus vaccine as well as a useful molecular marker vaccine against HP-PRRSV.

scholarly journals Complete Genome Sequence of a Recombinant Porcine Reproductive and Respiratory Syndrome Virus Strain from Two Genotype 1 Modified Live Virus Vaccine Strains

2017 ◽  
Vol 5 (22) ◽  
Author(s):  
Patricia Renson ◽  
Fabrice Touzain ◽  
Arnaud Lebret ◽  
Mireille Le Dimna ◽  
Hélène Quenault ◽  
...  
Keyword(s):  
Genome Sequence ◽  
Virus Vaccine ◽  
Complete Genome Sequence ◽  
Complete Genome ◽  
Respiratory Syndrome Virus ◽  
Genotype 1 ◽  
Live Virus ◽  
Live Virus Vaccine ◽  
Pig Farm ◽  
Prrsv Strain

ABSTRACT This paper provides information on the complete genome sequence of a porcine reproductive and respiratory syndrome virus (PRRSV) strain isolated on a French pig farm which was identified as a recombinant strain from two commercial modified live virus vaccine strains of genotype 1 (VP-046BIS and DV strains).

scholarly journals Identification of Virulence Associated Region during Highly Pathogenic Porcine Reproductive and Respiratory Syndrome Virus during Attenuation In Vitro: Complex Question with Different Strain Backgrounds

Viruses ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 40
Author(s):  
Yifeng Jiang ◽  
Wu Tong ◽  
Lingxue Yu ◽  
Liwei Li ◽  
Fei Gao ◽  
...  
Keyword(s):  
Virus Replication ◽  
Cytokine Response ◽  
Lung Damage ◽  
Respiratory Syndrome Virus ◽  
Cdna Clones ◽  
Highly Pathogenic ◽  
Prrsv Strain ◽  
Chimeric Viruses

Highly pathogenic porcine reproductive and respiratory syndrome virus PRRSV (HP-PRRSV) was one of the most devastating diseases of the pig industry, among various strategies, vaccination was one of the most useful tools for PRRS control. Attenuated live vaccine was used worldwide, however, the genetic basis of HP-PRRSV virulence change during attenuation remain to be determined. Here, to identify virulence associated regions of HP-PRRSV during attenuation in vitro, six full-length infectious cDNA clones with interchanges of 5′UTR + ORF1a, ORF1b, and ORF2-7 + 3′UTR regions between HP-PRRSV strain HuN4-F5 and its attenuated vaccine strain HuN4-F112 were generated, and chimeric viruses were rescued. Piglets were inoculated with chimeric viruses and their parental viruses, and rectal temperature were recorded daily, and serum were collected for future experiments. Our results showed that ORF1a played an important role on virus replication, cytokine response and lung damage, the exchange of ORF1b and ORF2-7 in different backbone led to different exhibition on virus replication in vivo/vitro and cytokine response. Among 9 PRRSV attenuated series, consistent amino acid changes during PRRSV attenuation were found in NSP4, NSP9, GP2, E, GP3 and GP4. Our study provides a fundamental data for the investigation of PRRSV attenuation, the different results of the virulence change among different studies indicated that different mechanisms might be used during PRRSV virulence enhancement in vivo and attenuation in vitro.

scholarly journals Peptide nanofiber hydrogel adjuvanted live virus vaccine enhances cross-protective immunity to porcine reproductive and respiratory syndrome virus

Vaccine ◽  
2013 ◽  
Vol 31 (41) ◽  
pp. 4508-4515 ◽  
Author(s):  
Xiangdong Li ◽  
Amy Galliher-Beckley ◽  
Hongzhou Huang ◽  
Xiuzhi Sun ◽  
Jishu Shi
Keyword(s):  
Virus Vaccine ◽  
Protective Immunity ◽  
Respiratory Syndrome Virus ◽  
Live Virus ◽  
Live Virus Vaccine

Commercial porcine reproductive and respiratory syndrome virus (PRRSV)-2 modified live virus vaccine against heterologous single and dual Korean PRRSV-1 and PRRSV-2 challenge

2018 ◽  
Vol 182 (17) ◽  
pp. 485-485 ◽  
Author(s):  
Jiwoon Jeong ◽  
Seeun Kim ◽  
Changhoon Park ◽  
Kee Hwan Park ◽  
Ikjae Kang ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Virus Vaccine ◽  
Interferon Γ ◽  
Growing Pigs ◽  
Respiratory Syndrome Virus ◽  
Live Virus ◽  
Lung Lesions ◽  
Viral Loads ◽  
Live Virus Vaccine ◽  
Ifn Γ

This study evaluated porcine reproductive and respiratory syndrome virus (PRRSV)-2 modified live virus (MLV) vaccine against heterologous single and dual challenge of Korean PRRSV-1 and PRRSV-2. Pigs were administered PRRSV-2 MLV vaccine intramuscularly at 21 days of age and inoculated intranasally with both genotypes at 56 days of age. Vaccination of pigs with PRRSV-2 MLV vaccine resulted in reduction of viral loads of both PRRSV-1 and PRRSV-2 after heterologous single and dual challenge with PRRSV-1 and PRRSV-2. In addition, pigs vaccinated with PRRSV-2 MLV vaccine exhibited higher frequencies of PRRSV-1 and PRRSV-2 specific interferon-γ secreting cells (IFN-γ-SC) and showed a significant reduction in lung lesions and PRRSV nucleic acid within the lung lesions after single and dual challenge compared with unvaccinated challenged pigs. Taken together these results demonstrated that vaccination of pigs with PRRSV-2 is efficacious in protecting growing pigs from respiratory disease against heterologous single and dual PRRSV-1 and PRRSV-2 challenge.

scholarly journals In Utero Infection by Porcine Reproductive and Respiratory Syndrome Virus Is Sufficient To Increase Susceptibility of Piglets to Challenge by Streptococcus suis Type II

2001 ◽  
Vol 75 (10) ◽  
pp. 4889-4895 ◽  
Author(s):  
Wen-hai Feng ◽  
S. M. Laster ◽  
M. Tompkins ◽  
T. Brown ◽  
J.-S. Xu ◽  
...  
Keyword(s):  
Streptococcus Suis ◽  
Dual Infection ◽  
In Utero ◽  
Respiratory Syndrome Virus ◽  
Type Ii ◽  
Infection Group ◽  
Bacterial Diseases ◽  
Prrs Virus ◽  
Young Pigs ◽  
Prrsv Strain

ABSTRACT Porcine reproductive and respiratory syndrome (PRRS) consistently elevates the frequency of disease and mortality in young pigs. Many different secondary bacterial diseases occur in PRRS virus (PRRSV)-infected pigs. However, to date, establishing a reproducible experimental model of PRRSV infection in weaned pigs, with subsequent clinical disease following secondary bacterial challenge, has been difficult. PRRSV is frequently isolated during outbreaks from weak-born piglets affected by secondary bacterial diseases. This study was performed to investigate the potential role of intrauterine PRRSV infection on piglet susceptibility to secondary bacterial infection. PRRSV-free pregnant sows were intranasally infected at 98 days of gestation with PRRSV strain SD 23983. All piglets born to the PRRSV-infected sows were viremic. Piglets were removed from the sows at birth and deprived of colostrum. Piglets from PRRSV-infected and noninfected sows were randomly assigned to Streptococcus suis challenge or control subgroups. At 5 days of age, piglets were challenged intranasally with strain MN 87555 of S. suis type II. Total and differential leukocyte counts were performed on blood samples collected at 3 days of age. The numbers of leukocytes, lymphocytes, and monocytes were significantly reduced in the PRRSV-infected piglets. Lesions were observed in bone marrow, brain, lung, heart, spleen, lymph node, tonsil, and thymus of PRRSV-infected piglets. Thymus/body weight ratios of in utero PRRSV-infected piglets were significantly reduced compared to those of non-PRRSV-infected piglets, and thymic lesions were characterized by severe cortical depletion of thymocytes. Lesions were not observed in piglets born to PRRSV-free sows. Overall, 20 out of 22 piglets in the PRRSV-S. suis dual-infection group died within 1 week after challenge with S. suis (10 of 11 in each of two trials). This contrasts with 1 of 18 piglets in the PRRSV-infection-only group and 5 of 23 piglets in the S. suis-challenge-only group (1 of 12 in trial 1 and 4 of 11 in trial 2). No piglets died in the uninfected control groups. Most of the piglets in the PRRSV-S. suis dual-infection group developed suppurative meningitis. S. suis type II was recovered from their brains and joints. These results indicate that in utero infection by PRRSV makes piglets more susceptible to infection and disease following challenge by S. suis type II. In utero infection by PRRSV may provide a useful model to study the interaction between PRRSV and bacterial coinfections in piglets.

scholarly journals Cross-protective immunity to porcine reproductive and respiratory syndrome virus by intranasal delivery of a live virus vaccine with a potent adjuvant

Vaccine ◽  
2011 ◽  
Vol 29 (23) ◽  
pp. 4058-4066 ◽  
Author(s):  
Varun Dwivedi ◽  
Cordelia Manickam ◽  
Ruthi Patterson ◽  
Katie Dodson ◽  
Michael Murtaugh ◽  
...  
Keyword(s):  
Virus Vaccine ◽  
Protective Immunity ◽  
Respiratory Syndrome Virus ◽  
Intranasal Delivery ◽  
Live Virus ◽  
Live Virus Vaccine

scholarly journals A Synthetic Porcine Reproductive and Respiratory Syndrome Virus Strain Confers Unprecedented Levels of Heterologous Protection

2015 ◽  
Vol 89 (23) ◽  
pp. 12070-12083 ◽  
Author(s):  
Hiep L. X. Vu ◽  
Fangrui Ma ◽  
William W. Laegreid ◽  
Asit K. Pattnaik ◽  
David Steffen ◽  
...  
Keyword(s):  
Reverse Genetics ◽  
Vaccine Coverage ◽  
Rna Virus ◽  
Respiratory Syndrome Virus ◽  
Full Genome ◽  
Genome Sequences ◽  
Prrsv Strain ◽  
Heterologous Protection

ABSTRACTCurrent vaccines do not provide sufficient levels of protection against divergent porcine reproductive and respiratory syndrome virus (PRRSV) strains circulating in the field, mainly due to the substantial variation of the viral genome. We describe here a novel approach to generate a PRRSV vaccine candidate that could confer unprecedented levels of heterologous protection against divergent PRRSV isolates. By using a set of 59 nonredundant, full-genome sequences of type 2 PRRSVs, a consensus genome (designated PRRSV-CON) was generated by aligning these 59 PRRSV full-genome sequences, followed by selecting the most common nucleotide found at each position of the alignment. Next, the synthetic PRRSV-CON strain was generated through the use of reverse genetics. PRRSV-CON replicates as efficiently as our prototype PRRSV strain FL12, bothin vitroandin vivo. Importantly, when inoculated into pigs, PRRSV-CON confers significantly broader levels of heterologous protection than does wild-type PRRSV. Collectively, our data demonstrate that PRRSV-CON can serve as an excellent candidate for the development of a broadly protective PRRSV vaccine.IMPORTANCEThe extraordinary genetic variation of RNA viruses poses a monumental challenge for the development of broadly protective vaccines against these viruses. To minimize the genetic dissimilarity between vaccine immunogens and contemporary circulating viruses, computational strategies have been developed for the generation of artificial immunogen sequences (so-called “centralized” sequences) that have equal genetic distances to the circulating viruses. Thus far, the generation of centralized vaccine immunogens has been carried out at the level of individual viral proteins. We expand this concept to PRRSV, a highly variable RNA virus, by creating a synthetic PRRSV strain based on a centralized PRRSV genome sequence. This study provides the first example of centralizing the whole genome of an RNA virus to improve vaccine coverage. This concept may be significant for the development of vaccines against genetically variable viruses that require active viral replication in order to achieve complete immune protection.

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