Efficacy of a Modified-Live PRRSV-1 Vaccine Administered to 1-Day-Old Piglets

 Pathogens

. 2021 Oct 18;10(10):1342.

 doi: 10.3390/pathogens10101342.

Efficacy of a Modified Live Virus Vaccine against Porcine Reproductive and Respiratory Syndrome Virus 1 (PRRSV-1) Administered to 1-Day-Old Piglets in Front of Heterologous PRRSV-1 Challenge

Heinrich Kreutzmann 1, Sophie Dürlinger 1, Christian Knecht 1, Michaela Koch 1, Marta Cabana 2, Gerard Torrent 2, Mònica Balasch 2, Lucas P Taylor 3, Gyula Balka 4, Wilhelm Gerner 5 6, Andrea Ladinig 1

Affiliations 

• PMID: 34684293
 
• PMCID: PMC8537468
 
• DOI: 10.3390/pathogens10101342

Free PMC article

Abstract

PRRSV is one of the most important viruses in the global swine industry and is often controlled by the use of modified live virus (MLV) vaccines. This study assessed the impact of a PRRSV-1 MLV vaccine applied to 1-day-old piglets challenged on day 28 of life with a PRRSV-1 field isolate (AUT15-33). Twenty-one piglets were vaccinated within 24 h of birth (T02), whereas 20 piglets were left unvaccinated (T01). Necropsy was performed two weeks post-challenge. Comparing the two groups, T02 piglets showed significantly higher (p = 0.017) average daily weight gain. In addition, significantly lower (p < 0.0001) PRRSV RNA loads were measured in serum of T02 piglets at all investigated time points. All T01 piglets were viremic and shed virus in nasal swabs, whereas only 71.4% and 38.1% of the T02 group were viremic or shed virus, respectively. Piglets from T02 had significantly higher numbers (p < 0.0001) of IFN-γ producing lymphocytes compared to T01. At necropsy, differences in gross and histologic lung lesions were statistically significant (p = 0.012 and p < 0.0001, respectively) between the two groups. Hence, this MLV vaccine administered to 1-day-old piglets was able to protect piglets against PRRSV infection at weaning.

Keywords: 1-day-old pigs; AUT15-33; IFN-γ; MLV; PRRSV; cellular immune response; shedding; vaccination; viremia.

Conflict of interest statement

M.C., G.T., M.B. and L.P.T. are employees from the sponsor company. They were involved in the design of the study, in sample collection, analyses of data and in the decision to publish the results as indicated in the Author Contributions

 Vet Microbiol

. 2021 Sep 20;262:109240.

 doi: 10.1016/j.vetmic.2021.109240. Online ahead of print.

Disinfection and conditions associated with thermo-assisted drying and decontamination inconsistently produce negative PRRSV rRT-PCR results on metal surfaces

Rita Anne Neat 1, Zhang Jianqiang 2, Hai Hoang 3, Lauren McKeen 4, Christine L Mowrer 5, Derald J Holtkamp 6

Affiliations 

Affiliations

• 1Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, 1800 Christensen Drive, Ames, IA, 50011, United States. Electronic address: ritaneat@iastate.edu.
• 2Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, 1800 Christensen Drive, Ames, IA, 50011, United States. Electronic address: jqzhang@iastate.edu.
• 3Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, 1800 Christensen Drive, Ames, IA, 50011, United States. Electronic address: hai.hoangthanh@hcmuaf.edu.vn.
• 4Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, 1800 Christensen Drive, Ames, IA, 50011, United States. Electronic address: lamckeen@iastate.edu.
• 5Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, 1800 Christensen Drive, Ames, IA, 50011, United States. Electronic address: clmowrer@iastate.edu.
• 6Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, 1800 Christensen Drive, Ames, IA, 50011, United States. Electronic address: holtkamp@iastate.edu.

• PMID: 34600200
 
• DOI: 10.1016/j.vetmic.2021.109240

Abstract

Because contaminated livestock trailers are a significant risk for transmitting viruses between herds, various methods of washing, disinfecting, and thermo-assisted drying and decontamination (TADD) have been evaluated for their effectiveness in inactivating porcine reproductive and respiratory syndrome virus (PRRSV) on contaminated surfaces. Information on when to expect negative qRT-PCR results after adequate trailer sanitation is lacking. The objective of this study was to evaluate whether there are conditions associated with washing-disinfectant-TADD procedures that will consistently produce a negative qRT-PCR result for the purpose of monitoring compliance with trailer sanitation and decontamination protocols for PRRSV on metal surfaces. 144 diamond plate aluminum coupons were spiked with PRRSV or phosphate-buffered saline (PBS) and treated with a designated disinfectant protocol. Disinfectants evaluated included multiple accelerated® hydrogen peroxide (AHP) disinfectants and a quaternary ammonium and glutaraldehyde combination disinfectant. Disinfectant was applied for 5 or 60 minutes of contact time at either 20 °C or -10 °C in a matrix of feces or PBS. All coupons were heated until the surface temperature of the coupon reached 71 °C and then held for 10 minutes to simulate TADD under field conditions. Post-treatment swabs for all treatment groups, except negative control groups, were positive by PRRSV qRT-PCR. Under the conditions evaluated in this study, consistently negative qRT-PCR results after treatments were not found. Therefore, for the purpose of monitoring compliance with trailer sanitation and decontamination protocols for PRRSV, alternatives to qRT-PCR should be explored.

Keywords: PCR; PRRSV; Swine; biosecurity.

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