Evaluation of Four Commercial Vaccines for the Protection of Piglets against the Highly Pathogenic Porcine Reproductive and Respiratory Syndrome Virus (hp-PRRSV) QH-08 Strain

Vaccination is the best way to prevent economic losses from highly pathogenic porcine reproductive and respiratory syndrome virus (hp-PRRSV) disease. However, the commercially available vaccines need to periodically evaluate their efficacy against infections caused by new hp-PRRSV variants. Therefore, the objective of this study was to evaluate the efficacy of four (two modified live vaccines (MLV) and two inactivated) PRRSV commercial vaccines in piglets challenged with QH-08 and to estimate the genetic distance of the vaccine strains from recently isolated (QH-08) filed strain. Randomly, piglets (n = 5) allocated in groups 1–4 were immunized with Ingelvac PRRS MLV, CH-1a, JXA1, and JXA1-RMLV vaccines, whereas the infected and non-infected control piglets in groups 5 and 6 (n = 3), respectively, were subjected to PBS. Results indicated that JXA1 and JXA1-R MLV vaccines showed complete protection, but Ingelvac PRRS MLV and CH-1α vaccines revealed partial protection against the QH-08 PRRSV challenge. Similarly, vaccinated and challenged pigs showed lower macroscopic and microscopic lesions than the pigs in group 5. Our findings demonstrated a new insight that the variation in ORF1a and 1b coding sequence could significantly affect PRRSV vaccines efficacy. In conclusion, QH-08 is a good candidate for the design and development of an innovative PRRSV vaccine that ultimately helps in the control and prevention strategies.

Download Full-text

Porcine Reproductive and Respiratory Syndrome Virus: Immune Escape and Application of Reverse Genetics in Attenuated Live Vaccine Development

Vaccines ◽

10.3390/vaccines9050480 ◽

2021 ◽

Vol 9 (5) ◽

pp. 480

Author(s):

Honglei Wang ◽

Yangyang Xu ◽

Wenhai Feng

Keyword(s):

Immune Responses ◽

Reverse Genetics ◽

Vaccine Development ◽

Immune Escape ◽

Rna Virus ◽

Economic Losses ◽

Respiratory Syndrome Virus ◽

Live Vaccines ◽

Host Immune Responses ◽

Inactivated Vaccines

Porcine reproductive and respiratory syndrome virus (PRRSV), an RNA virus widely prevalent in pigs, results in significant economic losses worldwide. PRRSV can escape from the host immune response in several processes. Vaccines, including modified live vaccines and inactivated vaccines, are the best available countermeasures against PRRSV infection. However, challenges still exist as the vaccines are not able to induce broad protection. The reason lies in several facts, mainly the variability of PRRSV and the complexity of the interaction between PRRSV and host immune responses, and overcoming these obstacles will require more exploration. Many novel strategies have been proposed to construct more effective vaccines against this evolving and smart virus. In this review, we will describe the mechanisms of how PRRSV induces weak and delayed immune responses, the current vaccines of PRRSV, and the strategies to develop modified live vaccines using reverse genetics systems.

Download Full-text

Highly Pathogenic Porcine Reproductive and Respiratory Syndrome Virus Induces Interleukin-17 Production via Activation of the IRAK1-PI3K-p38MAPK-C/EBPβ/CREB Pathways

Journal of Virology ◽

10.1128/jvi.01100-19 ◽

2019 ◽

Vol 93 (21) ◽

Cited By ~ 2

Author(s):

Honglei Wang ◽

Li Du ◽

Fang Liu ◽

Zeyu Wei ◽

Li Gao ◽

...

Keyword(s):

Lung Inflammation ◽

Molecular Mechanisms ◽

Nonstructural Protein ◽

Severe Pneumonia ◽

Pi3k Inhibitor ◽

Economic Losses ◽

Respiratory Syndrome Virus ◽

Binding Motif ◽

Interleukin 17 ◽

Highly Pathogenic

ABSTRACT Porcine reproductive and respiratory syndrome virus (PRRSV) is widely prevalent in pigs, resulting in significant economic losses worldwide. A compelling impact of PRRSV infection is severe pneumonia. In the present study, we found that interleukin-17 (IL-17) was upregulated by PRRSV infection. Subsequently, we demonstrated that PI3K and p38MAPK signaling pathways were essential for PRRSV-induced IL-17 production as addition of phosphatidylinositol 3-kinase (PI3K) and p38MAPK inhibitors dramatically reduced IL-17 production. Furthermore, we show here that deleting the C/EBPβ and CREB binding motif in porcine IL-17 promoter abrogated its activation and that knockdown of C/EBPβ and CREB remarkably impaired PRRSV-induced IL-17 production, suggesting that IL-17 expression was dependent on C/EBPβ and CREB. More specifically, we demonstrate that PRRSV nonstructural protein 11 (nsp11) induced IL-17 production, which was also dependent on PI3K-p38MAPK-C/EBPβ/CREB pathways. We then show that Ser74 and Phe76 amino acids were essential for nsp11 to induce IL-17 production and viral rescue. In addition, IRAK1 was required for nsp11 to activate PI3K and enhance IL-17 expression by interacting with each other. Importantly, we demonstrate that PI3K inhibitor significantly suppressed IL-17 production and lung inflammation caused by HP-PRRSV in vivo, implicating that higher IL-17 level induced by HP-PRRSV might be associated with severe lung inflammation. These findings provide new insights onto the molecular mechanisms of the PRRSV-induced IL-17 production and help us further understand the pathogenesis of PRRSV infection. IMPORTANCE Highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) associated with severe pneumonia has been one of the most important viral pathogens in pigs. IL-17 is a proinflammatory cytokine that might be associated with the strong inflammation caused by PRRSV. Therefore, we sought to determine whether PRRSV infection affects IL-17 expression, and if so, determine this might partially explain the underlying mechanisms for the strong inflammation in HP-PRRSV-infected pigs, especially in lungs. Here, we show that PRRSV significantly induced IL-17 expression, and we subsequently dissected the molecular mechanisms about how PRRSV regulated IL-17 production. Furthermore, we show that Ser74 and Phe76 in nsp11 were indispensable for IL-17 production and viral replication. Importantly, we demonstrated that PI3K inhibitor impaired IL-17 production and alleviated lung inflammation caused by HP-PRRSV infection. Our findings will help us for a better understanding of PRRSV pathogenesis.

Download Full-text

Genomic Analysis of a Highly Pathogenic Porcine Reproductive and Respiratory Syndrome Virus Circulating in Pig Farms in West China

Genome Announcements ◽

10.1128/genomea.00507-18 ◽

2018 ◽

Vol 6 (27) ◽

Author(s):

Chenyu Zhang ◽

Hu Shan ◽

Jianxin Wen

Keyword(s):

Genomic Analysis ◽

Economic Losses ◽

Respiratory Syndrome Virus ◽

Swine Industry ◽

Highly Pathogenic ◽

West China ◽

Pig Farms ◽

Long Time

Porcine reproductive and respiratory syndrome virus (PRRSV), which leads to tremendous economic losses worldwide, is currently one of the most threatening viruses for the swine industry. However, PRRSV outbreaks in West China are rarely reported, even though the virus has remained active for a long time across the country.

Download Full-text

Comparison of two genetically distant type 2 porcine reproductive and respiratory syndrome virus (PRRSV) modified live vaccines against Vietnamese highly pathogenic PRRSV

Veterinary Microbiology ◽

10.1016/j.vetmic.2015.06.013 ◽

2015 ◽

Vol 179 (3-4) ◽

pp. 233-241 ◽

Cited By ~ 15

Author(s):

Duy Tien Do ◽

Changhoon Park ◽

Kyuhyung Choi ◽

Jiwoon Jeong ◽

Toan Tat Nguyen ◽

...

Keyword(s):

Respiratory Syndrome Virus ◽

Highly Pathogenic ◽

Live Vaccines ◽

Highly Pathogenic Prrsv

Download Full-text

Efficacy of a live attenuated highly pathogenic PRRSV vaccine against a NADC30-like strain challenge: implications for ADE of PRRSV

BMC Veterinary Research ◽

10.1186/s12917-021-02957-z ◽

2021 ◽

Vol 17 (1) ◽

Author(s):

Xin-xin Chen ◽

Xinyu Zhou ◽

Tengda Guo ◽

Songlin Qiao ◽

Zhenhua Guo ◽

...

Keyword(s):

Neutralizing Antibodies ◽

Molecular Mechanisms ◽

Clinical Signs ◽

Bodyweight Gain ◽

Economic Losses ◽

Respiratory Syndrome Virus ◽

Experimental Conditions ◽

Highly Pathogenic ◽

Highly Pathogenic Prrsv

Abstract Background Porcine reproductive and respiratory syndrome virus (PRRSV) infection can cause severe reproductive failure in sows and respiratory distress in pigs of all ages, leading to major economic losses. To date, there are still no effective strategies to prevent and control PRRSV. Antibody-dependent enhancement (ADE), a phenomenon in which preexisting non-neutralizing antibodies or sub-neutralizing antibodies facilitate virus entry and replication, may be a significant obstacle in the development of effective vaccines for many viruses, including PRRSV. However, the contribution of ADE to PRRSV infection remains controversial, especially in vivo. Whether attenuated PRRSV vaccines prevent or worsen subsequent disease in pigs infected by novel PRRSV strains requires more research. In the present study, in vivo experiments were conducted to evaluate ADE under different immune statuses, which were produced by waiting different lengths of time after vaccination with a commercially available attenuated highly pathogenic PRRSV (HP-PRRSV) vaccine (JXA1-R) before challenging the pigs with a novel heterologous NADC30-like strain. Results Piglets that were vaccinated before being challenged with PRRSV exhibited lower mortality rates, lower body temperatures, higher bodyweight gain, and lower viremia. These results demonstrate that vaccination with JXA1-R alleviated the clinical signs of PRRSV infection in all vaccinated groups. Conclusions The obtained data indicate that the attenuated vaccine test here provided partial protection against the NADC30-like strain HNhx. No signs of enhanced PRRSV infection were observed under the applied experimental conditions. Our results provide some insight into the molecular mechanisms underlying vaccine-induced protection or enhancement in PRRSV.

Download Full-text

Efficacy Evaluation of Two Commercial Vaccines Against a Recombinant PRRSV2 Strain ZJnb16-2 From Lineage 8 and 3 in China

Pathogens ◽

10.3390/pathogens9010059 ◽

2020 ◽

Vol 9 (1) ◽

pp. 59

Author(s):

Guangwei Han ◽

Huiling Xu ◽

Yanli Wang ◽

Zehui Liu ◽

Fang He

Keyword(s):

Recombinant Virus ◽

Clinical Signs ◽

Neutralizing Antibody ◽

Cross Reactivity ◽

Daily Weight Gain ◽

Respiratory Syndrome Virus ◽

Efficacy Evaluation ◽

Partial Protection ◽

Live Vaccines ◽

Ifn Γ

From 2010, novel recombinant lineage 3 of porcine reproductive and respiratory syndrome virus 2 (PRRSV2) has continuously emerged China, which has brought about clinical outbreaks of the disease. Previously, a PRRSV2 strain named ZJnb16-2 was identified as a recombinant virus from lineage 8 and 3. In this study, two modified-live vaccines VR2332 MLV and HuN4-F112, which belong to lineage 5 and 8 respectively, were used for efficacy evaluation against the challenge of ZJnb16-2. Piglets vaccinated with HuN4-F112 exhibited temporary fever, higher average daily weight gain, and mild clinical signs as compared to VR2332 MLV vaccinated and unvaccinated piglets upon ZJnb16-2 challenge. Both vaccines could inhibit virus replication in piglets at 21days post challenge (DPC). Cross-reactivity of interferon (IFN)-γ secreting cells against ZJnb16-2 were detected in both vaccinated piglets. The number of IFN-γ secreting cells against ZJnb16-2 in the vaccination group exhibited sustaining elevation after challenge. Results demonstrated that both vaccines provided partial protection against ZJnb16-2 infection. A cross-neutralization antibody against ZJnb16-2 was not detected in any vaccinated piglet before challenge. A low neutralizing antibody titer against ZJnb16-2 was detected after challenge. Besides, all the vaccinated piglets suffered from different degrees of lung pathological lesions, indicating neither VR2332 MLV nor HuN4-F112 provided full protection against ZJnb16-2. This study provides valuable guidelines to control the recombinant virus from lineage 8 and 3 infection with MLV vaccines in the field.

Download Full-text

NADC30-Like Porcine Reproductive and Respiratory Syndrome in China

The Open Virology Journal ◽

10.2174/1874357901711010059 ◽

2017 ◽

Vol 11 (1) ◽

pp. 59-65 ◽

Cited By ~ 14

Author(s):

Kegong Tian

Keyword(s):

Virus Strain ◽

Current Situation ◽

Respiratory Syndrome Virus ◽

Complete Protection ◽

Highly Pathogenic ◽

High Incidence ◽

Genomic Characterization ◽

Virus Strains ◽

Highly Pathogenic Prrsv

NADC30-like porcine reproductive and respiratory syndrome virus (PRRSV) has widely spread in China and become locally dominant virus strain in some provinces. Although they are not pathogenic as highly pathogenic PRRSV (HP-RRRSV) that outbreaks since 2006, NADC30-like PRRSVs distinguished themselves by high incidence of recombination with other virus strains which lead to change of virulence. The outbreaks of NADC30-like PRRSV in the vaccinated pig herds suggested that current commercial PRRSV vaccines cannot provide complete protection to the infection. In this review, we have described in detail the current situation of NADC30 PRRSV including epidemiology, genomic characterization, pathogenicity, and efficacy of current commercial vaccines in China.

Download Full-text