scholarly journals PRRSV detection by qPCR in processing fluids and serum samples collected in a positive stable breeding herd following mass vaccination of sows with a modified live vaccine

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
A. Lebret ◽  
P. Berton ◽  
V. Normand ◽  
I. Messager ◽  
N. Robert ◽  
...  
Keyword(s):  
The United States ◽  
Live Vaccine ◽  
Mass Vaccination ◽  
Respiratory Syndrome Virus ◽  
Serum Samples ◽  
Blood Samples ◽  
Stability Monitoring ◽  
Breeding Herd ◽  
Modified Live Vaccine ◽  
Processing Fluid

AbstractIn the last two decades, in France, Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) stabilization protocols have been implemented using mass vaccination with a modified live vaccine (MLV), herd closure and biosecurity measures. Efficient surveillance for PRRSV is essential for generating evidence of absence of viral replication and transmission in pigs. The use of processing fluid (PF) was first described in 2018 in the United States and was demonstrated to provide a higher herd-level sensitivity compared with blood samples (BS) for PRRSV monitoring. In the meantime, data on vertical transmission of MLV viruses are rare even as it is a major concern. Therefore, veterinarians usually wait for several weeks after a sow mass vaccination before starting a stability monitoring. This clinical study was conducted in a PRRSV-stable commercial 1000-sow breed-to-wean farm. This farm suffered from a PRRS outbreak in January 2018. After implementing a stabilisation protocol, this farm was controlled as stable for more than 9 months before the beginning of the study. PF and BS at weaning were collected in four consecutive batches born after a booster sow mass MLV vaccination. We failed to detect PRRSV by qPCR on PF and BS collected in a positive-stable breeding herd after vaccination with ReproCyc® PRRS EU (Boehringer Ingelheim, Ingelheim, Germany).

scholarly journals Serodynamic Analysis of the Piglets Born from Sows Vaccinated with Modified Live Vaccine or E2 Subunit Vaccine for Classical Swine Fever

Pathogens ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 427 ◽  
Author(s):  
Yi-Chia Li ◽  
Ming-Tang Chiou ◽  
Chao-Nan Lin
Keyword(s):  
Detection Rate ◽  
Time Window ◽  
Classical Swine Fever ◽  
Significant Negative Correlation ◽  
Live Vaccine ◽  
Economic Losses ◽  
Respiratory Syndrome Virus ◽  
Serum Samples ◽  
Significant Difference ◽  
Modified Live Vaccine

Classical swine fever (CSF) caused by the CSF virus (CSFV) is one of the most important swine diseases, resulting in huge economic losses to the pig industry worldwide. Systematic vaccination is one of the most effective strategies for the prevention and control of this disease. Two main CSFV vaccines, the modified live vaccine (MLV) and the subunit E2 vaccine, are recommended. In Taiwan, CSF cases have not been reported since 2006, although systemic vaccination has been practiced for 70 years. Here, we examined the sero-dynamics of the piglets born from sows that received either the CSFV MLV or the E2 vaccine and investigated in the field the correlation between the porcine reproductive and respiratory syndrome virus (PRRSV) loads and levels of CSFV antibody. A total of 1398 serum samples from 42 PRRSV-positive farms were evaluated to determine the PRRSV loads by real-time PCR and to detect CSFV antibody levels by commercial ELISA. Upon comparing the two sow vaccination protocols (CSFV MLV vaccination at 4 weeks post-farrowing versus E2 vaccination at 4–5 weeks pre-farrowing), the lowest levels of CSFV antibody were found in piglets at 5–8 and 9–12 weeks of age for the MLV and E2 groups, respectively. Meanwhile, the appropriate time window for CSFV vaccination of offspring was at 5–8 and 9–12 weeks of age in the MLV and E2 groups, respectively. There was a very highly significant negative correlation between the PRRSV load and the level of CSFV antibody in the CSFV MLV vaccination group (P < 0.0001). The PRRSV detection rate in the pigs from the MLV group (27.78%) was significantly higher than that in pigs from the E2 group (21.32%) (P = 0.011). In addition, there was a significant difference (P = 0.019) in the PRRSV detection rate at 5–8 weeks of age between the MLV (42.15%) and E2 groups (29.79%). Our findings indicate that the vaccination of CSFV MLV in piglets during the PRRSV susceptibility period at 5–8 weeks of age may be overloading the piglet’s immune system and should be a critical concern for industrial pork production in the field.

scholarly journals Effects of North American Porcine Reproductive and Respiratory Syndrome Virus (PRRSV)-Based Modified Live Vaccines on Preimmunized Sows Artificially Inseminated with European PRRSV-Spiked Semen

2012 ◽  
Vol 19 (3) ◽  
pp. 319-324 ◽  
Author(s):  
Kiwon Han ◽  
Hwi Won Seo ◽  
Yeonsu Oh ◽  
Ikjae Kang ◽  
Changhoon Park ◽  
...  
Keyword(s):  
North American ◽  
Animal Health ◽  
Negative Control ◽  
Live Vaccine ◽  
Reproductive Failure ◽  
Respiratory Syndrome Virus ◽  
Serum Samples ◽  
The North ◽  
Group 2 ◽  
Modified Live Vaccine

ABSTRACTThe objective of the present study was to determine if the European porcine reproductive and respiratory syndrome virus (PRRSV) can be transmitted via spiked semen to preimmunized sows and induce reproductive failure. Sows were immunized with the North American PRRSV-based modified live vaccine (Ingelvac PRRS MLV; Boehringer Ingelheim Animal Health, St. Joseph, MO) and were artificially inseminated. The sows were randomly divided into three groups. The vaccinated (group 2) and nonvaccinated (group 3) sows developed a PRRSV viremia at 7 to 28 days postinsemination with the European PRRSV-spiked semen. The number of genomic copies of the European PRRSV in serum samples was not significantly different between vaccinated and nonvaccinated sows. All negative-control sows in group 1 farrowed at the expected date. The sows in groups 2 and 3 farrowed between 103 and 110 days after the first insemination. European PRRSV RNA was detected in the lungs of 8 out of 11 live-born piglets and 46 out of 54 stillborn fetuses. In addition, PRRSV RNA was detected usingin situhybridization in other tissues from vaccinated sows that had been inseminated with European PRRSV-spiked semen (group 2). The present study has demonstrated that vaccinating sows with the North American PRRSV-based modified live vaccine does not prevent reproductive failure after insemination with European PRRSV-spiked semen.

scholarly journals A Novel Mucosal Adjuvant System for Immunization against Avian Coronavirus Causing Infectious Bronchitis

2020 ◽  
Vol 94 (19) ◽  
Author(s):  
Shaswath S. Chandrasekar ◽  
Brock Kingstad-Bakke ◽  
Chia-Wei Wu ◽  
M. Suresh ◽  
Adel M. Talaat
Keyword(s):  
United States ◽  
Nucleic Acid ◽  
Infectious Bronchitis Virus ◽  
The United States ◽  
Live Vaccine ◽  
Clinical Severity ◽  
Live Vaccines ◽  
Infectious Bronchitis ◽  
Adjuvant System ◽  
Modified Live Vaccine

ABSTRACT Infectious bronchitis (IB) caused by infectious bronchitis virus (IBV) is currently a major threat to chicken health, with multiple outbreaks being reported in the United States over the past decade. Modified live virus (MLV) vaccines used in the field can persist and provide the genetic material needed for recombination and emergence of novel IBV serotypes. Inactivated and subunit vaccines overcome some of the limitations of MLV with no risk of virulence reversion and emergence of new virulent serotypes. However, these vaccines are weakly immunogenic and poorly protective. There is an urgent need to develop more effective vaccines that can elicit a robust, long-lasting immune response. In this study, we evaluate a novel adjuvant system developed from Quil-A and chitosan (QAC) for the intranasal delivery of nucleic acid immunogens to improve protective efficacy. The QAC adjuvant system forms nanocarriers (<100 nm) that efficiently encapsulate nucleic acid cargo, exhibit sustained release of payload, and can stably transfect cells. Encapsulation of plasmid DNA vaccine expressing IBV nucleocapsid (N) protein by the QAC adjuvant system (pQAC-N) enhanced immunogenicity, as evidenced by robust induction of adaptive humoral and cellular immune responses postvaccination and postchallenge. Birds immunized with pQAC-N showed reduced clinical severity and viral shedding postchallenge on par with protection observed with current commercial vaccines without the associated safety concerns. Presented results indicate that the QAC adjuvant system can offer a safer alternative to the use of live vaccines against avian and other emerging coronaviruses. IMPORTANCE According to 2017 U.S. agriculture statistics, the combined value of production and sales from broilers, eggs, turkeys, and chicks was $42.8 billion. Of this number, broiler sales comprised 67% of the industry value, with the production of >50 billion pounds of chicken meat. The economic success of the poultry industry in the United States hinges on the extensive use of vaccines to control infectious bronchitis virus (IBV) and other poultry pathogens. The majority of vaccines currently licensed for poultry health include both modified live vaccine and inactivated pathogens. Despite their proven efficacy, modified live vaccine constructs take time to produce and could revert to virulence, which limits their safety. The significance of our research stems from the development of a safer and potent alternative mucosal vaccine to replace live vaccines against IBV and other emerging coronaviruses.

Porcine reproductive and respiratory syndrome virus (PRRSv) modified-live vaccine reduces virus transmission in experimental conditions

Vaccine ◽  
2015 ◽  
Vol 33 (21) ◽  
pp. 2493-2499 ◽  
Author(s):  
N. Rose ◽  
P. Renson ◽  
M. Andraud ◽  
F. Paboeuf ◽  
M.F. Le Potier ◽  
...  
Keyword(s):  
Virus Transmission ◽  
Live Vaccine ◽  
Respiratory Syndrome Virus ◽  
Experimental Conditions ◽  
Modified Live Vaccine

Antibody reaction in immunologically naïve replacement gilts vaccinated with an attenuated PRRSV live vaccine

2014 ◽  
Vol 42 (02) ◽  
pp. 95-99 ◽  
Author(s):  
A. Düngelhoef ◽  
S. Lösken ◽  
E. grosse Beilage
Keyword(s):  
Infectious Diseases ◽  
Cost Effective ◽  
Vaccine Virus ◽  
Live Vaccine ◽  
Field Conditions ◽  
Rt Pcr ◽  
Serum Samples ◽  
Serological Reaction ◽  
Blood Samples ◽  
Antibody Reaction

Summary Objective: Serological testing of blood samples is commonly known as an approved method to diagnose infectious diseases. Likewise it is used for monitoring infectious diseases as it is fast and cost-effective. Nevertheless interpretation of results can be difficult, especially when the samples were taken from animals, which received a vaccination prior to the serological examination. This is mainly due to the fact, that not every vaccination induces a measurable antibody reaction. In this recent case gilts were vaccinated with an attenuated live vaccine and the serum samples were negative in the ELISA. The question aroused which serological reaction to a vaccine is expected under field conditions. Material and methods: In order to clarify this question a group of 28 gilts negative for porcine reproductive and respiratory syndrome (PRRS) virus (from a verifiable PRRSV-negative stock) were vaccinated with an attenuated PRRSV vaccine and blood samples were taken on days 0, 2, 4, 8 and 15 post vaccinationem (p. vacc). To provide a reliable means of diagnosis the samples were tested with an antibody ELISA and RT-PCR. Results: A replication of the vaccine virus was demonstrated via RT-PCR in 100% of the animals 4 days p. vacc. The first samples classified positive in the ELISA were detected 8 days p. vacc. On day 15 p. vacc. a positive serological result was obtained for all animals. Conclusion: The vaccination with an attenuated PRRSV vaccine provides a pronounced antibody reaction under field conditions. In case of a negative serological reaction in recently vaccinated pigs all steps from the manufacturing process through to the implementation of the vaccine have to be critically evaluated. Likewise correct laboratory studies and the assessment of diagnostic results need to be scrutinized.

scholarly journals Impacts of Quarterly Sow Mass Vaccination with a Porcine Reproductive and Respiratory Syndrome Virus Type 1 (PRRSV-1) Modified Live Vaccine in Two Herds

Vaccines ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1057
Author(s):  
Kasper Pedersen ◽  
Charlotte Sonne Kristensen ◽  
Lise Kirstine Kvisgaard ◽  
Lars Erik Larsen
Keyword(s):  
Negative Impact ◽  
Mass Vaccination ◽  
Respiratory Syndrome Virus ◽  
Nursery Pigs ◽  
Prrs Virus ◽  
Before And After ◽  
Strain Virus ◽  
Modified Live Vaccine ◽  
Paired Design ◽  
The Impact

In recent years, there has been a considerable increase in the use of Modified Live PRRSV Vaccines (MLV) for mass vaccination in Denmark. The potential risks and negative impact of this strategy have been sparsely studied. The aim of this study was to investigate the impact of quarterly sow mass vaccination in two Danish sow herds. The study was performed as an observational prospective cohort of 120 sows in each of two commercial breeding herds in a paired design. Blood samples were taken from sows and oral fluid samples from nursery pigs (four to ten weeks old) before and after vaccination. The presence of PRRSV-1 RNA was measured by real time quantitative reverse transcription-polymerase chain reaction (RT-qPCR), and the level of PRRSV-1 specific antibodies was measured by two different serological assays. PRRS virus was not detected in the sow herds two days before and two weeks after vaccination, but the vaccine strain virus was detected in the nursery pigs. The prevalence of sows without antibodies towards PRRSV-1 went from 6–15% before vaccination to 1–4% after vaccination depending on the serological assay used, despite the fact that they had previously been repeatedly vaccinated. Four sows tested negative for antibodies in both assays after vaccination.

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