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

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.

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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

Veterinary Record ◽

10.1136/vr.104397 ◽

2018 ◽

Vol 182 (17) ◽

pp. 485-485 ◽

Cited By ~ 2

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.

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Tilmicosin Reduces PRRSV Loads in Pigs in vivo

Journal of Agricultural Science ◽

10.5539/jas.v8n1p154 ◽

2015 ◽

Vol 8 (1) ◽

pp. 154

Author(s):

Chao-Nan Lin ◽

Yu-Jian Yang ◽

Wei-Hao Lin ◽

Hsien-Ching Wu ◽

Zhixuan Xiong ◽

...

Keyword(s):

Macrolide Antibiotic ◽

Treated Group ◽

Daily Weight Gain ◽

Average Daily Weight Gain ◽

Weaned Piglets ◽

Swine Industry ◽

The Impact ◽

Porcine Respiratory

Porcine respiratory and reproductive syndrome virus (PRRSV) is an important pathogen having a significant economic impact on the swine industry worldwide. Tilmicosin is a new semi-synthetic macrolide antibiotic developed from tylosin B. Tilmicosin can enter pulmonary alveolar macrophages (PAMs) and inhibit the replication of PRRSV in PAMs in vitro. This study was conducted to evaluate the impact of tilmicosin in controlling the replication of PRRSV in vivo. Forty and 635 weaned piglets were randomly chosen from PRRSV-contaminated farrow-to-finish herds in Taiwan and China, respectively. The piglets were equally divided into two groups and housed in the same pen but separated into individual spaces. Tilmicosin (Tilmovet® 20% premix, 400 mg/kg) was administered after weaning for 21 days (treated group). The untreated group of piglets did not receive tilmicosin. Blood samples were collected at 4, 6, 8, 10 and 12 weeks of age to detect of the PRRSV load. At 8 and 10 weeks of age, the tilmicosin-treated piglets had a significantly lower PRRSV load than the untreated piglets (P < 0.05) in Taiwan. At 6, 8, 10, and 12 weeks of age, the tilmicosin-treated piglets had a significantly lower PRRSV load than the untreated piglets (P < 0.05) in China. These data indicates that animals treated with tilmicosin exhibited not only reduced PRRSV loads but also improved average daily weight gain during the study period.

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A Comparison of Virulence of Three Porcine Circovirus Type 2 (PCV2) Genotypes (a, b, and d) in Pigs Singularly Inoculated with PCV2 and Dually Inoculated with PCV2 and Porcine Reproductive and Respiratory Syndrome Virus

Pathogens ◽

10.3390/pathogens10070891 ◽

2021 ◽

Vol 10 (7) ◽

pp. 891

Author(s):

Jeongmin Suh ◽

Taehwan Oh ◽

Keehwan Park ◽

Siyeon Yang ◽

Hyejean Cho ◽

...

Keyword(s):

Porcine Circovirus Type ◽

Porcine Circovirus Type 2 ◽

Daily Weight Gain ◽

Porcine Circovirus ◽

Respiratory Syndrome Virus ◽

Average Daily Weight Gain ◽

Significant Difference ◽

Lesion Severity ◽

Severe Lung

The aim of this study was to compare the virulence of porcine circovirus type 2 (PCV2) genotypes in dually inoculated pigs with both three genotypes (a, b, and d) of PCV2 and porcine reproductive and respiratory syndrome virus-2 (PRRSV-2) versus pigs singularly inoculated with the same three PCV2 genotypes (a, b, and d). Differences in this comparison were found in PCV2 viremia levels, lung and lymphoid lesion severity, and the amount of PCV2 antigen within the lymphoid lesions. Regardless of PCV2 genotypes, pigs that were dually inoculated with PCV2/PRRSV had significantly higher clinical scores, less average daily weight gain, higher levels of PCV2 viremia, and more severe lug and lymphoid lesions compared to pigs singularly inoculated with PCV2. Among the dually infected pig groups, pigs infected with PCV2d/PRRSV-2 had significantly higher levels of PCV2 viremia, more severe lung and lymphoid lesions, and more PCV2-positive cells within lymphoid lesions compared to pigs dually inoculated with PCV2a/PRRSV-2 and PCV2b/PRRSV-2. The results of this study demonstrated significant differences in the virulence among dual inoculation of PCV2a/PRRSV-2, PCV2b/PRRSV-2, and PCV2d/PRRSV-2. A significant difference in the virulence among PCV2a, PCV2b, and PCV2d single-inoculated pig groups was not found with respect to the levels of PCV2 viremia and production of PCV2-associated lymphoid lesions.

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The Function of the PRRSV–Host Interactions and Their Effects on Viral Replication and Propagation in Antiviral Strategies

Vaccines ◽

10.3390/vaccines9040364 ◽

2021 ◽

Vol 9 (4) ◽

pp. 364

Author(s):

Jun Ma ◽

Lulu Ma ◽

Meiting Yang ◽

Wei Wu ◽

Wenhai Feng ◽

...

Keyword(s):

Immune Response ◽

Molecular Mechanisms ◽

Immune Escape ◽

Rna Virus ◽

Economic Losses ◽

Respiratory Syndrome Virus ◽

Swine Industry ◽

Live Virus ◽

Virus Challenge ◽

Host Interactions

Porcine reproductive and respiratory syndrome virus (PRRSV) affects the global swine industry and causes disastrous economic losses each year. The genome of PRRSV is an enveloped single-stranded positive-sense RNA of approximately 15 kb. The PRRSV replicates primarily in alveolar macrophages of pig lungs and lymphatic organs and causes reproductive problems in sows and respiratory symptoms in piglets. To date, studies on how PRRSV survives in the host, the host immune response against viral infections, and pathogenesis, have been reported. PRRSV vaccines have been developed, including inactive virus, modified live virus, attenuated live vaccine, DNA vaccine, and immune adjuvant vaccines. However, there are certain problems with the durability and effectiveness of the licensed vaccines. Moreover, the high variability and fast-evolving populations of this RNA virus challenge the design of PRRSV vaccines, and thus effective vaccines against PRRSV have not been developed successfully. As is well known, viruses interact with the host to escape the host’s immune response and then replicate and propagate in the host, which is the key to virus survival. Here, we review the complex network and the mechanism of PRRSV–host interactions in the processes of virus infection. It is critical to develop novel antiviral strategies against PRRSV by studying these host–virus interactions and structures to better understand the molecular mechanisms of PRRSV immune escape.

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Efficacy of a modified-live virus vaccine in pigs experimentally infected with a highly pathogenic porcine reproductive and respiratory syndrome virus type 1 (HP-PRRSV-1)

Veterinary Microbiology ◽

10.1016/j.vetmic.2018.10.001 ◽

2018 ◽

Vol 226 ◽

pp. 89-96 ◽

Cited By ~ 6

Author(s):

Elena Canelli ◽

Alessia Catella ◽

Paolo Borghetti ◽

Luca Ferrari ◽

Giulia Ogno ◽

...

Keyword(s):

Virus Type ◽

Virus Vaccine ◽

Respiratory Syndrome Virus ◽

Highly Pathogenic ◽

Live Virus ◽

Live Virus Vaccine

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

Genome Announcements ◽

10.1128/genomea.00454-17 ◽

2017 ◽

Vol 5 (22) ◽

Cited By ~ 5

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).

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

Vaccine ◽

10.1016/j.vaccine.2013.07.080 ◽

2013 ◽

Vol 31 (41) ◽

pp. 4508-4515 ◽

Cited By ~ 28

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

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

Vaccine ◽

10.1016/j.vaccine.2011.03.006 ◽

2011 ◽

Vol 29 (23) ◽

pp. 4058-4066 ◽

Cited By ~ 42

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

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Porcine Circovirus Type 2 Infection Decreases the Efficacy of a Modified Live Porcine Reproductive and Respiratory Syndrome Virus Vaccine

Clinical and Vaccine Immunology ◽

10.1128/cvi.00074-06 ◽

2006 ◽

Vol 13 (8) ◽

pp. 923-929 ◽

Cited By ~ 46

Author(s):

T. Opriessnig ◽

N. E. McKeown ◽

K. L. Harmon ◽

X. J. Meng ◽

P. G. Halbur

Keyword(s):

Age Groups ◽

Porcine Circovirus Type ◽

Porcine Circovirus Type 2 ◽

Pcv2 Infection ◽

Daily Weight Gain ◽

Porcine Circovirus ◽

Respiratory Syndrome Virus ◽

Live Virus ◽

Lymphoid Depletion

ABSTRACT Porcine reproductive and respiratory syndrome virus (PRRSV)-induced pneumonia is a major problem, and vaccination is used to reduce losses associated with PRRSV. Porcine circovirus type 2 (PCV2) causes lymphoid depletion, and there is concern that this adversely affects the immune response. The objective of this study was to investigate the effect of PCV2 infection on the efficacy of modified live virus (MLV) PRRSV vaccine. Sixty-nine 2-week-old pigs were randomly assigned to one of seven groups of 9 to 10 pigs each. At 6 weeks of age, pigs in groups 4, 5, and 6 were inoculated intranasally with PCV2 ISU-40895. At 8 weeks of age, groups 3, 4, 6, and 7 were vaccinated with a PRRSV MLV vaccine. At 12 weeks of age, groups 2, 3, and 4 were challenged with PRRSV SDSU73. All pigs were necropsied 14 days after PRRSV challenge. PCV2-infected, PRRSV-vaccinated, and PRRSV-challenged pigs had significantly (P < 0.05) more-severe macroscopic lung lesions than did the PRRSV-vaccinated and PRRSV-challenged pigs that were not exposed to PCV2 prior to PRRSV vaccination. Nonvaccinated PRRSV-infected pigs had a significantly (P < 0.001) higher incidence of PRRSV antigen in lungs than did all other groups except the group infected with PCV2 prior to PRRSV vaccination and challenge. The nonvaccinated PRRSV-challenged group and the group challenged with PCV2 prior to PRRSV vaccination and challenge had significantly (P < 0.001) lower average daily weight gain than did the control and the vaccinated groups. This work suggests that PCV2 infection has an adverse effect on the development of protective immunity induced by PRRSV vaccine.

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The Impact of Neonatal ICU Single Family Rooms on Select Developmental Outcomes

10.28971/532011dl93 ◽

2011 ◽

Author(s):

Lynda D'Alessio

Keyword(s):

Weight Gain ◽

Retrospective Chart Review ◽

Time Frame ◽

Daily Weight Gain ◽

Single Family ◽

Average Daily Weight Gain ◽

Family Unit ◽

Practice Nurses ◽

Neonatal Icu ◽

The Impact

The purpose of this study was to determine if there is a weight gain benefit and earlier achievement to full feedings in the single family room NICU design compared to the multi-bed NICU design. A retrospective chart review of infants less than 1000 grams born during a three month time frame in both the multi-bed unit and single family unit was conducted. The study compared average daily weight gain and achievement to full feedings in the multi-bed unit and single family room unit. Findings concluded there was a slight difference in the average daily weight gain and achievement to full feedings occurred several days earlier in the single family room unit. In the single family unit the advanced practice nurses are able to promote a family-centered environment by encouraging rooming in, Kangaroo care, and breastfeeding, all of which were nearly impossible for the parents to accomplish in the multi-bed unit due to lack of space and pr1vacy.

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