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1.
J Vet Med Sci ; 82(2): 224-228, 2020 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-31866631

RESUMO

The objective of this study was to compare the efficacy of a porcine reproductive and respiratory syndrome virus (PRRSV)-1 and PRRSV-2 modified-live virus (MLV) vaccines when administered at 1 day of age under field conditions. The piglets elicited anti-PRRSV antibodies at 1 day of age even in the presence of maternally derived antibodies. The number of PRRSV-2 genomic copies in the sera of pigs from the PRRSV-2 MLV-vaccinated pigs was significantly (P<0.05) lower when compared to PRRSV-1 MLV-vaccinated pigs. The average daily gain in PRRSV-2 MLV-vaccinated pigs was significantly (P<0.05) higher when compared to both PRRSV-1 MLV-vaccinated and unvaccinated pigs. This study demonstrated that vaccination as early as 1 day of age was effective against PRRSV infection.

2.
Vet Microbiol ; 239: 108497, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31767085

RESUMO

The objective of this study was to evaluate the effect of concurrent vaccination with a porcine reproductive and respiratory syndrome virus (PRRSV)-1 modified-live virus (MLV) vaccine and a PRRSV-2 MLV vaccine against a dual heterologous PRRSV-1 and PRRSV-2 challenge in late term pregnancy gilts. Gilts were concurrently administered PRRSV-1 and PRRSV-2 MLV vaccines at 21 days prior to breeding at separate anatomical sites and were inoculated intranasally with both PRRSV types at 93 days of gestation. Vaccinated gilts had a higher number of live-born and weaned pigs, and a decrease in stillbirths compared to the unvaccinated control group following a dual challenge. Concurrent vaccination resulted also in the reduction of both PRRSV-1 and PRRSV-2 viremia which correlated with an increase in the number of PRRSV-1 and PRRSV-2 specific interferon-γ secreting cells (IFN-γ-SC). We believe the T cell responses contributed to the reduction of both PRRSV-1 and PRRSV-2 viremia. The results presented here demonstrate that concurrent vaccination with PRRSV-1 and PRRSV-2 MLV vaccines improves reproductive performance, reduces viremia of PRRSV-1 and PRRSV-2, and induces protective T cell reactions against dual PRRSV-1 and PRRSV-2 challenge in late term pregnancy gilts without local and systemic adverse reactions related to concurrent vaccination.


Assuntos
Síndrome Respiratória e Reprodutiva Suína/prevenção & controle , Vírus da Síndrome Respiratória e Reprodutiva Suína/imunologia , Vacinação/veterinária , Vacinas Atenuadas/imunologia , Vacinas Virais/imunologia , Animais , Anticorpos Antivirais/sangue , Feminino , Gravidez , Resultado da Gravidez/veterinária , Suínos , Vacinação/normas , Viremia/prevenção & controle , Viremia/veterinária
3.
Can J Vet Res ; 83(4): 248-254, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31571723

RESUMO

The objective of the present study was to evaluate the efficacy of a commercial porcine reproductive and respiratory syndrome virus (PRRSV) subunit vaccine against heterologous PRRSV-1 and PRRSV-2 challenge in late-term pregnant gilts. Gilts were vaccinated intramuscularly 56 and 35 days antepartum (on days 58 and 79 of gestation) and challenged intranasally 21 days antepartum (on day 93 of gestation) with PRRSV-1 or PRRSV-2. Regardless of the challenge strain's genotype, the vaccinated gilts carried their pregnancies to term and farrowed between days 114 and 115 of gestation. All the unvaccinated gilts aborted, between days 105 and 110 of gestation. The vaccinated gilts had a significantly lower level (P < 0.05) of PRRSV viremia and significantly higher levels (P < 0.05) of virus-neutralizing antibodies and interferon-γ-secreting cells compared with the unvaccinated gilts. The mean number of PRRSV-positive cells per area of fetal tissue examined did not differ significantly between the litters from the vaccinated and unvaccinated gilts. The data presented here indicate that vaccination in late-term pregnancy with PRRSV subunit vaccine is efficacious against reproductive failure due to heterologous PRRSV-1 and PRRSV-2 infection.


Assuntos
Síndrome Respiratória e Reprodutiva Suína/prevenção & controle , Vírus da Síndrome Respiratória e Reprodutiva Suína/classificação , Complicações Infecciosas na Gravidez/veterinária , Vacinas Virais/imunologia , Animais , Feminino , Vírus da Síndrome Respiratória e Reprodutiva Suína/imunologia , Gravidez , Complicações Infecciosas na Gravidez/prevenção & controle , Subunidades Proteicas , Suínos , Vacinas de Subunidades/imunologia , Proteínas Virais/imunologia
4.
BMC Vet Res ; 15(1): 342, 2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31619295

RESUMO

BACKGROUND: The objective of this study was to assess the efficacy of a trivalent vaccine mixture and compare it to the respective monovalent vaccines against Mycoplasma hyopneumoniae, porcine circovirus type 2 (PCV2), and porcine reproductive and respiratory syndrome virus (PRRSV). RESULTS: Pigs that were triple challenged with M. hyopneumoniae, PCV2, and PRRSV following vaccination with the trivalent vaccine mixture exhibited a significantly better growth performance when compared to unvaccinated and challenged pigs. A statistical difference was not found when comparing pig populations which were vaccinated with the trivalent vaccine followed by a triple challenge and pigs vaccinated with monovalent M hyopneumoniae vaccine followed by mycoplasmal single challenge in the following areas: M. hyopneumoniae nasal shedding, the number of M. hyopneumoniae-specific interferon-γ secreting cells (IFN-γ-SC), and mycoplasmal lung lesion scores. Pigs vaccinated with the trivalent vaccine mixture followed by a triple challenge resulted in a similar reduction of PCV2 viremia, an increase in the number of PCV2-specific IFN-γ-SC and reduction in interstitial lung lesion scores when compared to pigs vaccinated with a PCV-2 vaccine and challenged with PCV2 only. Lastly, there was a significant difference in the reduction of PRRSV viremia, an increase in PRRSV-specific IFN-γ-SC and a reduction of interstitial lung lesion scores between pigs vaccinated with the trivalent vaccine mixture followed by a triple challenge and pigs vaccinated with a monovalent PRRSV vaccine followed by PRRSV challenge only. CONCLUSION: The trivalent vaccine mixture was efficacious against a triple challenge of M. hyopneumoniae, PCV2, and PRRSV. The trivalent vaccine mixture, however, did not result in equal protection when compared against each respective monovalent vaccine, with the largest vaccine occurring within PRRSV.


Assuntos
Circovirus/imunologia , Mycoplasma hyopneumoniae/imunologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/imunologia , Doenças dos Suínos/prevenção & controle , Vacinação/veterinária , Animais , Vacinas Bacterianas/imunologia , Infecções por Circoviridae/imunologia , Infecções por Circoviridae/prevenção & controle , Feminino , Masculino , Pneumonia Suína Micoplasmática/imunologia , Pneumonia Suína Micoplasmática/prevenção & controle , Síndrome Respiratória e Reprodutiva Suína/imunologia , Síndrome Respiratória e Reprodutiva Suína/prevenção & controle , Sus scrofa , Suínos , Doenças dos Suínos/imunologia , Doenças dos Suínos/microbiologia , Doenças dos Suínos/virologia , Vacinas Combinadas/administração & dosagem , Vacinas Combinadas/imunologia , Vacinas Virais/imunologia
5.
Can J Vet Res ; 83(2): 110-121, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31097873

RESUMO

The efficacy of a porcine reproductive and respiratory syndrome (PRRS) subunit vaccine was evaluated and compared with a modified-live virus (MLV) vaccine under field conditions. Three farms were selected based on their history of respiratory diseases caused by co-infection with both PRRSV-1 and PRRSV-2. In each farm, 60 pigs were randomly allocated to 2 vaccinated and 1 unvaccinated groups (20 pigs per group). One group of pigs were administered the PRRS subunit vaccine at 21 and 42 days of age and another group administered the PRRS MLV vaccine at 21 days of age. The subunit vaccine had similar efficacy and, in some instances, performed even better than the MLV vaccine. Vaccination of pigs with either of the PRRS vaccines resulted in significantly improved growth performance in Farm B but not in Farm C. In Farm A, pigs vaccinated with the PRRS subunit vaccine had a better growth performance statistically compared to those vaccinated with the PRRS MLV vaccine. At the peak of PRRSV-1 and PRRSV-2 viremia, neutralizing antibodies and T-cell responses against PRRSV-1 and PRRSV-2 were at low levels suggesting that either vaccine is only able to provide a partial protection against co-circulating PRRSV-1 and PRRSV-2.


Assuntos
Síndrome Respiratória e Reprodutiva Suína/prevenção & controle , Vacinas Virais/imunologia , Animais , Anticorpos Antivirais/sangue , Interferon gama , Filogenia , Vírus da Síndrome Respiratória e Reprodutiva Suína , RNA Viral/sangue , RNA Viral/genética , Distribuição Aleatória , Suínos
6.
Vet Microbiol ; 231: 87-92, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30955830

RESUMO

The objective of this study was to compare the efficacy of a commercial porcine circovirus type 2a (PCV2a) subunit vaccine against experimental PCV2a, PCV2b, and PCV2d challenge. A total of 105 pigs were randomly divided into 7 groups (15 pigs per group). At 21 days old the pigs were intramuscularly administered the PCV2a vaccine as a 1.0 mL dose. Four weeks following vaccination, pigs were challenged with either Korean PCV2a, PCV2b, or PCV2d. All vaccinated pigs showed a significant (P < 0.05) reduction of clinical signs, PCV2 viremia, lymphoid lesions, and lymphoid PCV2 antigen levels compared to unvaccinated control pigs. Vaccination resulted also in significantly higher (P < 0.05) titers of neutralizing antibody against PCV2, and an increase in the frequency of PCV2-specific interferon-γ secreting cells (IFN-γ-SC). The vaccine showed similar protection among the vaccinated groups regardless of the genotype of the challenge. Interestingly, vaccinated pigs had higher levels of neutralizing antibody titers against PCV2a compared to PCV2b or PCV2d while the number of PCV2a-, PCV2b-, and PCV2d-specific IFN-γ-SC were similar. Taken together, the results presented here demonstrate that a PCV2a vaccine can be effective against experimental PCV2a, PCV2b, and PCV2d challenge.


Assuntos
Anticorpos Antivirais/sangue , Infecções por Circoviridae/veterinária , Doenças dos Suínos/prevenção & controle , Vacinas Virais/uso terapêutico , Animais , Anticorpos Neutralizantes/sangue , Infecções por Circoviridae/imunologia , Infecções por Circoviridae/prevenção & controle , Circovirus/genética , Circovirus/imunologia , DNA Viral/sangue , Fazendas , Genótipo , Injeções Intramusculares , Interferon gama/imunologia , Gado , Distribuição Aleatória , Suínos , Doenças dos Suínos/imunologia , Vacinação , Vacinas de Subunidades/imunologia , Vacinas de Subunidades/uso terapêutico , Vacinas Virais/imunologia
7.
Artigo em Inglês | MEDLINE | ID: mdl-30961820

RESUMO

The efficacy of four commercial porcine reproductive and respiratory syndrome virus (PRRSV) modified-live virus (MLV) vaccines against respiratory disease was evaluated and compared in pig farms suffering from co-infection with PRRSV-1 and PRRSV-2. All vaccinated groups on average exhibited improved growth rate compared to the unvaccinated pigs. Interestingly, the two groups vaccinated with either of the PRRSV-2 MLV vaccines had a better overall growth rate compared to the pigs vaccinated with either of the PRRSV-1 MLV vaccines. Vaccination of pigs with either of the PRRSV-1 MLV vaccines did not result in reduction of PRRSV-1 or PRRSV-2 viremia whereas vaccination of pigs with either of the PRRSV-2 MLV vaccines resulted in the reduction of PRRSV-2 viremia only. Taken together, the results of this field study demonstrate that a PRRSV-2 MLV vaccine can be efficacious against respiratory disease caused by co-infection with PRRSV-1 and PRRSV-2.


Assuntos
Síndrome Respiratória e Reprodutiva Suína/prevenção & controle , Vírus da Síndrome Respiratória e Reprodutiva Suína/imunologia , Vacinação/veterinária , Vacinas Atenuadas/imunologia , Vacinas Virais/imunologia , Animais , Anticorpos Antivirais/sangue , Coinfecção/virologia , Fazendas , Tipagem Molecular , Síndrome Respiratória e Reprodutiva Suína/imunologia , Síndrome Respiratória e Reprodutiva Suína/virologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/classificação , Vírus da Síndrome Respiratória e Reprodutiva Suína/genética , Suínos
8.
Can J Vet Res ; 83(1): 57-67, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30670903

RESUMO

The efficacy of 4 commercial porcine reproductive and respiratory syndrome virus (PRRSV) modified-live vaccines (MLV), against PRRSV-1 and PRRSV-2 was evaluated and compared in growing pigs. Two of the vaccines were based on PRRSV-1 and two on PRRSV-2. There were no significant differences between each of the two PRRSV-1 MLV vaccines and the two PRRSV-2 MLV vaccines respectively based on virology, immunological, and pathological evaluations. Vaccination with either of the PRRSV-1 MLV vaccines resulted in reduced PRRSV-1 but not PRRSV-2 viremia. Additionally, vaccination with either of the PRRSV-1 MLV vaccines resulted in reduction of lung lesions and PRRSV-1 positive cells in PRRSV-1 challenged pigs but had no significant effect in PRRSV-2 challenged pigs. In contrast, vaccination with either of the two PRRSV-2 MLV vaccines resulted in the reduction of both PRRSV-1 and PRRSV-2 viremia. The PRRSV-2 MLV vaccines were also able to effectively reduce lung lesions and PRRSV positive cells after challenge with either PRRSV-1 or PRRSV-2. Our data suggest that while vaccination with PRRSV-1 MLV vaccines can be effective against PRRSV-1, only PRRSV-2 MLV vaccines can protect against both Korean PRRSV-1 and PRRSV-2 challenges in this study.


Assuntos
Síndrome Respiratória e Reprodutiva Suína/prevenção & controle , Vírus da Síndrome Respiratória e Reprodutiva Suína/classificação , Vacinas Virais/imunologia , Animais , Interferon gama , Síndrome Respiratória e Reprodutiva Suína/epidemiologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/imunologia , RNA Viral/sangue , Distribuição Aleatória , República da Coreia/epidemiologia , Suínos , Viremia
9.
Vet Microbiol ; 223: 119-125, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30173737

RESUMO

We have evaluated the cross-protection of a modified-live virus (MLV) vaccine based on porcine reproductive and respiratory syndrome virus (PRRSV)-2, against a heterologous PRRSV-1 challenge in late term pregnancy gilts. Gilts were vaccinated 42 days prior to breeding and then challenged intranasally with PRRSV-1 at 93 days of gestation. No local or systemic adverse effects related to vaccination were observed in the vaccinated gilts throughout the study. Vaccination resulted in a longer gestation period, a higher number of live-born and weaned piglets, and a significant decrease in the number of stillborn piglets compared to the unvaccinated group. The PRRSV-2 MLV vaccine was also able to significantly reduce PRRSV-1 viremia. At the time of PRRSV-1 challenge, vaccinated gilts had significantly higher PRRSV-1 specific interferon-γ secreting cells but low neutralizing antibody titers against PRRSV-1 compared to unvaccinated gilts. This correlated with a reduction of PRRSV-1 viremia, indicating that cell-mediated rather than humoral immunity played a role in PRRSV-1 clearance from the blood. Fetal thymic tissues from vaccinated pregnant gilts had fewer PRRSV-1 positive cells compared to unvaccinated gilts. Taken together these results indicate that vaccination of gilts with PRRSV-2 MLV vaccine can provide cross-protection against PRRSV-1 challenge and improve reproductive performance.


Assuntos
Administração Intranasal/veterinária , Síndrome Respiratória e Reprodutiva Suína/prevenção & controle , Vírus da Síndrome Respiratória e Reprodutiva Suína/imunologia , Reprodução , Vacinas Virais/imunologia , Animais , Anticorpos Neutralizantes/imunologia , Proteção Cruzada , Feminino , Feto/virologia , Interferon gama/metabolismo , Síndrome Respiratória e Reprodutiva Suína/virologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/genética , Gravidez , Natimorto/veterinária , Suínos , Vacinação/veterinária , Vacinas Atenuadas/imunologia , Viremia/veterinária , Desmame
10.
J Vet Med Sci ; 80(9): 1463-1467, 2018 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-30022776

RESUMO

The objective of this study was to compare the efficacy of a commercial porcine reproductive and respiratory syndrome (PRRS) subunit vaccine and a prototype PRRS II subunit vaccine against a highly pathogenic PRRS virus (HP-PRRSV) in pigs. Both vaccines were administered intramuscularly in 2 doses at 21 and 42 days of age, and the pigs were challenged intranasally with HP-PRRSV at 63 days of age. Pigs vaccinated with the prototype PRRS II subunit vaccine had significantly higher anti-PRRSV antibody titers, a greater number of interferon-γ-secreting cells, and a greater reduction in lung lesion scores compared to pigs vaccinated with the commercial PRRS subunit vaccine. Therefore, the commercial PRRS subunit and prototype PRRS II subunit vaccines are efficacious against HP-PRRSV.


Assuntos
Anticorpos Antivirais/sangue , Síndrome Respiratória e Reprodutiva Suína/prevenção & controle , Vírus da Síndrome Respiratória e Reprodutiva Suína/imunologia , Suínos , Vacinas Virais/imunologia , Animais , Vacinas Atenuadas , Vacinas de Subunidades , Vacinas Virais/administração & dosagem
11.
Transbound Emerg Dis ; 65(6): 1641-1647, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29877065

RESUMO

The objective of this study was to compare the severity of reproductive failure caused by either a single or a dual infection with porcine reproductive and respiratory syndrome virus (PRRSV)-1 and PRRSV-2 in late-term pregnancy gilts. Pregnant gilts were intranasally administered PRRSV-1, PRRSV-2 or both at 3 weeks before the expected farrowing date (93 days of gestation). Regardless of single and dual infection, PRRSV-infected pregnant gilts experienced premature farrowing (103-109 days of gestation) compared with negative control gilts which carried their pregnancy to full term (114-115 days of gestation). Pregnant gilts infected with only PRRSV-1 had a significantly (p < 0.05) higher number of genomic copies of PRRSV-1 in their blood compared with dually infected gilts. Additionally, stillborn foetuses and live-born piglets from pregnant gilts infected with only PRRSV-1 had a significantly (p < 0.05) higher number of PRRSV-1-positive cells per unit area of tissue sections examined, compared to pregnant gilts dually infected with PRRSV-1 and PRRSV-2. In contrast, pregnant gilts infected with only PRRSV-2 showed no difference in the number of genomic copies of PRRSV-2 compared with dually infected pregnant gilts and there were no significant differences in PRRSV-2-positive cells per unit area in tissues of stillborn foetuses and live-born piglets from pregnant gilts infected with PRRSV-2 only compared with dually infected gilts. Interestingly, even though PRRSV-2 was shown to replicate more efficiently compared with PRRSV-1 in dually infected pregnant gilts, neither PRRSV type was able to exacerbate reproductive failure in pregnant gilts already dually infected with PRRSV-1 and PRRSV-2. Our results suggest that the severity of reproductive failure is similar between dual (PRRSV-1 and PRRSV-2) and single infection (PRRSV-1 or PRRSV-2).


Assuntos
Síndrome Respiratória e Reprodutiva Suína/patologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/patogenicidade , Complicações Infecciosas na Gravidez/veterinária , Prenhez , Administração Intranasal , Animais , Feminino , Morte Fetal , Feto/virologia , Síndrome Respiratória e Reprodutiva Suína/virologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/genética , Vírus da Síndrome Respiratória e Reprodutiva Suína/isolamento & purificação , Gravidez , Complicações Infecciosas na Gravidez/virologia , Natimorto , Sus scrofa , Suínos
12.
Can J Vet Res ; 82(2): 146-153, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29755195

RESUMO

A novel porcine circovirus type 2 (PCV2) peptide vaccine comprised of a consensus capsid (Cap) protein domain encoded by open reading frame 2 was developed to control PCV2 infection. The efficacy of the vaccine was evaluated against a commercial baculovirus-expressed recombinant PCV2 subunit vaccine based on the Cap protein. The amino acid sequence of this Cap protein was designed based on the alignment of amino acid sequences from different isolates from Europe, North America, and Asia. The vaccine was evaluated in either phosphate-buffered saline or adjuvanted with aluminum hydroxide, cobalt oxide, or liposome. Overall the PCV2 peptide vaccine was less efficacious against PCV2 challenge compared with the commercial PCV2 vaccine. The peptide vaccine was the most efficacious when liposome was used as an adjuvant, significantly (P < 0.05) reducing viremia while increasing the levels of neutralizing antibodies and interferon-γ secreting cells. This suggests, in the presence of liposome, the peptide vaccine was able to elicit both humoral and cellular immune responses.


Assuntos
Infecções por Circoviridae/veterinária , Circovirus/classificação , Doenças dos Suínos/prevenção & controle , Vacinas Virais/imunologia , Animais , Anticorpos Neutralizantes/sangue , Infecções por Circoviridae/prevenção & controle , Infecções por Circoviridae/virologia , Circovirus/imunologia , DNA Viral/sangue , Interferon gama/metabolismo , Suínos , Doenças dos Suínos/virologia , Vacinas de Subunidades/imunologia , Vacinas Sintéticas/imunologia
13.
Vet Rec ; 182(21): 602, 2018 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-29545353

RESUMO

The objective of this field study was to evaluate the reproductive performance of sows after vaccination with a porcine reproductive and respiratory syndrome (PRRS) subunit vaccine (PRRSFREE PRRS subunit vaccine, Reber Genetics, Taiwan, Republic of China) under field conditions. The study was performed in three farms with endemic infections with both PRRS virus (PRRSV)-1 and PRRSV-2, a situation representative of most Korean farms. Pregnant sows were immunised intramuscularly with 2.0 ml of the PRRS subunit vaccine at 58 and 79 days of gestation (eight and five weeks antepartum) according to the manufacturer's recommendation. Vaccination did not result in any observed adverse reaction. Vaccinated sows exhibited a significant improvement in reproductive performance (reduction of abortions) and litter characteristics (increase of weaned pigs) compared with unvaccinated sows. Vaccinated sows had significantly (P<0.05) higher PRRSV ELISA sample/positive ratio and number of PRRSV-specific interferon-γ-secreting cells compared with the unvaccinated control group. The results of this study demonstrate that the PRRS subunit vaccine can improve the reproductive performance of sows in farms with endemic PRRSV infection.


Assuntos
Doenças Endêmicas/veterinária , Síndrome Respiratória e Reprodutiva Suína/prevenção & controle , Reprodução/fisiologia , Vacinas Virais/administração & dosagem , Animais , Doenças Endêmicas/prevenção & controle , Fazendas , Feminino , Síndrome Respiratória e Reprodutiva Suína/epidemiologia , Síndrome Respiratória e Reprodutiva Suína/virologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/genética , Vírus da Síndrome Respiratória e Reprodutiva Suína/isolamento & purificação , Gravidez , RNA Viral/sangue , Suínos , Taiwan/epidemiologia , Vacinas de Subunidades/administração & dosagem
14.
Vet Rec ; 182(17): 485, 2018 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-29472439

RESUMO

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.


Assuntos
Síndrome Respiratória e Reprodutiva Suína/prevenção & controle , Vírus da Síndrome Respiratória e Reprodutiva Suína/imunologia , Vacinação/veterinária , Vacinas Virais/imunologia , Administração Intranasal , Animais , Genótipo , Injeções Intramusculares , Síndrome Respiratória e Reprodutiva Suína/imunologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/genética , Suínos , Vacinação/métodos , Vacinas Atenuadas/administração & dosagem , Vacinas Atenuadas/imunologia , Carga Viral/veterinária , Vacinas Virais/administração & dosagem
15.
Can J Vet Res ; 82(1): 39-47, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29382967

RESUMO

The objective of this study was to compare clinical, microbiologic, immunologic, and pathologic parameters in pigs each concurrently administered porcine reproductive and respiratory syndrome virus (PRRSV), Mycoplasma hyopneumoniae, and porcine circovirus type 2 (PCV2) vaccine from 1 of 2 commercial sources at 21 days of age and challenged with field strains of each of the 3 pathogens. Pigs were challenged with PRRSV and M. hyopneumoniae at 42 days of age (-14 days post-challenge, dpc) followed by a challenge with PCV2 at 56 days of age (0 dpc). Significant differences were observed between vaccinated challenged and unvaccinated challenged groups in clinical (average daily gain and clinical signs), microbiologic (viremia and nasal shedding), immunologic (antibodies and interferon-γ secreting cells), and pathologic (lesions) outcomes. Significant differences were observed among the 3 vaccinated challenged groups in microbiologic (nasal shedding of M. hyopneumoniae and viremia of PCV2) and immunologic (M. hyopneumoniae- and PCV2-specific interferon-γ secreting cells) outcomes. The vaccination regimen for PRRSV vaccine, M. hyopneumoniae vaccine, and PCV2 vaccine is efficacious for controlling triple challenge with PRRSV, M. hyopneumoniae, and PCV2 from weaning to finishing period.


Assuntos
Infecções por Circoviridae/veterinária , Circovirus , Pneumonia Suína Micoplasmática/prevenção & controle , Síndrome Respiratória e Reprodutiva Suína/prevenção & controle , Vacinação/veterinária , Animais , Vacinas Bacterianas/administração & dosagem , Vacinas Bacterianas/imunologia , Infecções por Circoviridae/imunologia , Infecções por Circoviridae/prevenção & controle , Circovirus/classificação , Circovirus/imunologia , DNA Viral/sangue , Mycoplasma hyopneumoniae/imunologia , Pneumonia Suína Micoplasmática/microbiologia , Síndrome Respiratória e Reprodutiva Suína/virologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/imunologia , RNA Viral/sangue , Suínos , Doenças dos Suínos/microbiologia , Doenças dos Suínos/prevenção & controle , Doenças dos Suínos/virologia , Fatores de Tempo , Vacinas Virais/administração & dosagem , Vacinas Virais/imunologia , Viremia/veterinária
16.
Vet Microbiol ; 214: 113-124, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29408022

RESUMO

A porcine reproductive and respiratory syndrome virus (PRRSV) modified live-virus (MLV) vaccine was evaluated under field conditions for registration as recommended by the Republic of Korea's Animal, Plant & Fisheries Quarantine & Inspection Agency. A single dose of the vaccine was administered to 1-day-old piglets and their growth performance was monitored under field conditions. Three separate farms were selected based on their history of PRRSV-associated respiratory diseases. On each farm, 40 pigs were randomly allocated to one of two treatment groups: (i) vaccinated (n = 20) and (ii) unvaccinated (n = 20) pigs at 1 day of age. Vaccinated pigs showed an increase of their market weight of 6.23 kg/pig compared to the unvaccinated pigs (98.01 kg in vaccinated group vs. 91.78 kg in unvaccinated group; P < 0.05) and exhibited a decrease in mortality rate by 6.7% (3.3% in vaccinated group vs. 10% in unvaccinated group; P < 0.05). The pigs had a sufficiently mature immune system for the vaccine to elicit humoral and cell-mediated immunity (as measured by anti-PRRSV antibodies and PRRSV-specific interferon-γ secreting cells, respectively) at 1 day of age even in the presence of maternally derived antibodies. The results presented in this study demonstrate that the PRRSV MLV vaccine is effective in improving growth performance from day 1 all the way to day 182 in endemic farms suffering with PRRSV-2 infection or both PRRSV-1 and PRRSV-2 infection.


Assuntos
Síndrome Respiratória e Reprodutiva Suína/prevenção & controle , Vírus da Síndrome Respiratória e Reprodutiva Suína/imunologia , Vacinação/veterinária , Vacinas Virais/imunologia , Animais , Animais Recém-Nascidos , Anticorpos Antivirais , Fazendas , Imunidade Celular , Imunidade Humoral , Imunidade Materno-Adquirida , Interferon gama/imunologia , Síndrome Respiratória e Reprodutiva Suína/epidemiologia , Síndrome Respiratória e Reprodutiva Suína/imunologia , Síndrome Respiratória e Reprodutiva Suína/virologia , República da Coreia/epidemiologia , Suínos , Vacinas Atenuadas/imunologia , Vacinas Virais/administração & dosagem
17.
Vet Microbiol ; 208: 47-52, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28888648

RESUMO

The efficacy of a porcine reproductive and respiratory syndrome (PRRS) modified-live virus vaccine in reproductive performance was evaluated under field conditions. Three PRRS endemic farms were selected based on their history of PRRS-associated reproductive failures. On each farm, a total of 40 sows were randomly allocated to either vaccinated (n=20) or unvaccinated (n=20) groups. Sows were vaccinated six weeks prior to breeding. Clinical data showed a significant improvement in reproductive performance in vaccinated sows. Sows in the vaccinated groups had a significantly (P<0.05) reduced number of stillborn piglets in all 3 farms. Sows in the vaccinated groups also had a significantly (P<0.05) higher number of live-born piglets in one of the farms. Sows in the vaccinated groups had a significantly (P<0.05) higher number of weaned piglets in two of the farms. Premature farrowing, one of the late gestation symptoms of PRRS, was also reduced due to vaccination as suggested by the increase in gestation length and the reduction in the number of stillborn piglets. No adverse systemic or local side effects relative to vaccination were observed during the entire gestation. No vaccine strain was detected in the vaccinated sows from all three farms at 70 and 114days post vaccination and in live-born piglets at the time of farrowing. Vaccination of sows with this PRRS vaccine was effective in improving reproductive performance in endemic PRRS farms.


Assuntos
Síndrome Respiratória e Reprodutiva Suína/prevenção & controle , Vacinas Virais/imunologia , Animais , Feminino , Tamanho da Ninhada de Vivíparos , Vírus da Síndrome Respiratória e Reprodutiva Suína , Gravidez , RNA Viral , Suínos , Vacinas Atenuadas
18.
Can J Vet Res ; 81(3): 171-177, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28725106

RESUMO

The objective of this study was to compare the protection against challenge with porcine circovirus 2 (PCV2) induced by an experimental vaccine based on open reading frame (ORF) 2 of PCV2 DNA plus an adjuvant (aluminum hydroxide, cobalt oxide, or liposome) and a commercial PCV2 subunit vaccine. A total of 35 colostrum-fed, cross-bred, conventional piglets were randomly divided into 7 groups. The commercial vaccine was more efficacious against PCV2 challenge than the 4 experimental vaccines according to immunologic, virologic, and pathological outcomes. The pigs inoculated with the experimental vaccine containing the liposome adjuvant had significantly higher levels (P < 0.05) of neutralizing antibodies and interferon-γ-secreting cells, and significantly lower levels (P < 0.05) of PCV2 viremia than the pigs inoculated with the other experimental vaccines. The pigs inoculated with the experimental vaccines containing either the liposome adjuvant or the cobalt oxide adjuvant had significantly lower lymphoid lesion scores (P < 0.05) than the pigs in the group inoculated with the PCV2 DNA vaccine dissolved in phosphate-buffered saline. Liposome proved to be a potent adjuvant that efficiently enhanced both humoral and cellular immune responses induced by the PCV2 DNA vaccine.


Assuntos
Circovirus/genética , DNA Viral/imunologia , Doenças dos Suínos/prevenção & controle , Vacinas Virais/imunologia , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Imunidade Celular , Interferon gama , Fases de Leitura Aberta , Plasmídeos , Suínos , Doenças dos Suínos/virologia , Vacinas de DNA
19.
Can J Vet Res ; 81(2): 108-117, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28408778

RESUMO

The objective of the present study was to determine the effect of concurrent vaccination of boars with type 1 and type 2 porcine reproductive and respiratory syndrome virus (PRRSV) on seminal shedding of both genotypes. The boars tolerated well concurrent administration of 2 commercial PRRSV vaccines, and no adverse reactions were observed. No interference in the humoral immune response (measured as the level of anti-PRRSV antibodies) or the cell-mediated immune response (measured as the level of PRRSV-specific interferon-γ-secreting cells) was observed after concurrent administration compared with single administration of the same vaccines. Concurrent vaccination significantly reduced the load of type 1 and type 2 PRRSV in blood and semen after singular (type 1 or type 2) and dual (type 1 and type 2) PRRSV challenge, and it did not significantly affect the efficacy of each vaccine. The results demonstrate that concurrent vaccination of boars with type 1 and type 2 PRRSV reduces shedding of both genotypes in semen.


Assuntos
Síndrome Respiratória e Reprodutiva Suína/prevenção & controle , Vírus da Síndrome Respiratória e Reprodutiva Suína/classificação , Sêmen/virologia , Vacinas Virais/imunologia , Eliminação de Partículas Virais , Animais , Anticorpos Antivirais/sangue , Masculino , Síndrome Respiratória e Reprodutiva Suína/sangue , Síndrome Respiratória e Reprodutiva Suína/virologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/fisiologia , Suínos
20.
Vet Microbiol ; 192: 102-109, 2016 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-27527771

RESUMO

Type 2 porcine reproductive and respiratory syndrome (PRRS) virus (PRRSV) was first isolated in Korea in 1994. The commercial PRRS modified live vaccine (Ingelvac(®) PRRS MLV, Boehringer Ingelheim Vetmedica Inc., St. Joseph, Missouri, USA) based on type 2 PRRSV, was first licensed for use in 3- to 18-week-old pigs in Korea in 1996. The objective of the present study was to evaluate the efficacy of this 20year old commercial PRRS modified live vaccine (MLV) against two recent PRRSV isolates. Two genetically distant type 2 PRRSV strains (SNUVR150004 for lineage 1 and SNUVR150324 for lineage 5), isolated in 2015, were used as challenge virus. Regardless of the challenge virus, vaccination of pigs effectively reduced the level of viremia, the lung lesions, and of the PRRSV antigen within the lung lesions. The induction of virus-specific interferon-γ secreting cells by the PRRS vaccine produced a protective immune response, leading to the reduction of PRRSV viremia. There were no significant differences in efficacy against the two recently isolated viruses by the PRRS MLV based on virological results, immunological responses, and pathological outcomes. This study demonstrates that the PRRS MLV used in this study is still effective against recently isolated heterologous type 2 PRRSV strains even after 20 years of use in over 35 million pigs.


Assuntos
Síndrome Respiratória e Reprodutiva Suína/prevenção & controle , Vírus da Síndrome Respiratória e Reprodutiva Suína/classificação , Vacinas Virais/imunologia , Animais , Regulação Viral da Expressão Gênica , Filogenia , Vírus da Síndrome Respiratória e Reprodutiva Suína/genética , RNA Viral/sangue , Suínos , Proteínas do Envelope Viral/genética
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