Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.685
Filtrar
1.
Biomed Environ Sci ; 33(9): 670-679, 2020 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-33106212

RESUMEN

Objective: In China, 24 cases of human infection with highly pathogenic avian influenza (HPAI) H5N6 virus have been confirmed since the first confirmed case in 2014. Therefore, we developed and assessed two H5N6 candidate vaccine viruses (CVVs). Methods: In accordance with the World Health Organization (WHO) recommendations, we constructed two reassortant viruses using reverse genetics (RG) technology to match the two different epidemic H5N6 viruses. We performed complete genome sequencing to determine the genetic stability. We assessed the growth ability of the studied viruses in MDCK cells and conducted a hemagglutination inhibition assay to analyze their antigenicity. Pathogenicity attenuation was also evaluated in vitro and in vivo. Results: The results showed that no mutations occurred in hemagglutinin or neuraminidase, and both CVVs retained their original antigenicity. The replication capacity of the two CVVs reached a level similar to that of A/Puerto Rico/8/34 in MDCK cells. The two CVVs showed low pathogenicity in vitro and in vivo, which are in line with the WHO requirements for CVVs. Conclusion: We obtained two genetically stable CVVs of HPAI H5N6 with high growth characteristics, which may aid in our preparedness for a potential H5N6 pandemic.


Asunto(s)
Virus de la Influenza A/inmunología , Vacunas contra la Influenza/inmunología , Gripe Aviar/epidemiología , Gripe Aviar/prevención & control , Gripe Humana/epidemiología , Gripe Humana/prevención & control , Pandemias/prevención & control , Animales , Aves , China , Humanos
2.
Avian Pathol ; 49(6): 529-531, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32720513

RESUMEN

COVID-19 should be a "call to arms" for the poultry industry to reassess containment of the H9N2 subtype of low pathogenicity avian influenza viruses. Strains of this virus are a human pandemic threat and a severe economic burden on poultry production. Over the past 20 years they have spread throughout Asia, Africa, Middle East and parts of Europe. As a global industry, a critical need is to re-imagine production and marketing chains, especially in low and middle-income countries, where the structure of much of the industry facilitates virus transmission, especially, but not only, in improperly managed live poultry markets and related value chains. Better, appropriately matched vaccines are needed to support this process but such vaccines cannot, alone, overcome the existing defects in biosecurity, including high farm densities. None of this will occur unless the threat posed by this virus to global health security is recognized.


Asunto(s)
Betacoronavirus , Infecciones por Coronavirus/epidemiología , Subtipo H9N2 del Virus de la Influenza A , Gripe Aviar/virología , Gripe Humana/virología , Neumonía Viral/epidemiología , Animales , Aves , Infecciones por Coronavirus/virología , Salud Global , Humanos , Gripe Aviar/epidemiología , Gripe Aviar/prevención & control , Gripe Humana/epidemiología , Gripe Humana/prevención & control , Pandemias , Neumonía Viral/virología , Aves de Corral/virología
3.
J Neuropathol Exp Neurol ; 79(8): 823-842, 2020 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-32647884

RESUMEN

Biological evolution of the microbiome continually drives the emergence of human viral pathogens, a subset of which attack the nervous system. The sheer number of pathogens that have appeared, along with their abundance in the environment, demand our attention. For the most part, our innate and adaptive immune systems have successfully protected us from infection; however, in the past 5 decades, through pathogen mutation and ecosystem disruption, a dozen viruses emerged to cause significant neurologic disease. Most of these pathogens have come from sylvatic reservoirs having made the energetically difficult, and fortuitously rare, jump into humans. But the human microbiome is also replete with agents already adapted to the host that need only minor mutations to create neurotropic/toxic agents. While each host/virus symbiosis is unique, this review examines virologic and immunologic principles that govern the pathogenesis of different viral CNS infections that were described in the past 50 years (Influenza, West Nile Virus, Zika, Rift Valley Fever Virus, Hendra/Nipah, Enterovirus-A71/-D68, Human parechovirus, HIV, and SARS-CoV). Knowledge of these pathogens provides us the opportunity to respond and mitigate infection while at the same time prepare for inevitable arrival of unknown agents.


Asunto(s)
Enfermedades Virales del Sistema Nervioso Central/epidemiología , Enfermedades Virales del Sistema Nervioso Central/transmisión , Zoonosis/epidemiología , Zoonosis/transmisión , Animales , Aves , Enfermedades Virales del Sistema Nervioso Central/prevención & control , Ecosistema , Humanos , Gripe Aviar/epidemiología , Gripe Aviar/prevención & control , Gripe Aviar/transmisión , Gripe Humana/epidemiología , Gripe Humana/prevención & control , Gripe Humana/transmisión , Fiebre del Nilo Occidental/epidemiología , Fiebre del Nilo Occidental/prevención & control , Fiebre del Nilo Occidental/transmisión , Infección por el Virus Zika/epidemiología , Infección por el Virus Zika/prevención & control , Infección por el Virus Zika/transmisión , Zoonosis/prevención & control
4.
Biomed J ; 43(4): 375-387, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32611537

RESUMEN

BACKGROUND: Highly pathogenic emerging and re-emerging viruses continuously threaten lives worldwide. In order to provide prophylactic prevention from the emerging and re-emerging viruses, vaccine is suggested as the most efficient way to prevent individuals from the threat of viral infection. Nonetheless, the highly pathogenic viruses need to be handled in a high level of biosafety containment, which hinders vaccine development. To shorten the timeframe of vaccine development, the pseudovirus system has been widely applied to examine vaccine efficacy or immunogenicity in the emerging and re-emerging viruses. METHODS: We developed pseudovirus systems for emerging SARS coronavirus 2 (SARS-CoV-2) and re-emerging avian influenza virus H5 subtypes which can be handled in the biosafety level 2 facility. Through the generated pseudovirus of SARS-CoV-2 and avian influenza virus H5 subtypes, we successfully established a neutralization assay to quantify the neutralizing activity of antisera against the viruses. RESULTS: The result of re-emerging avian influenza virus H5Nx pseudoviruses provided valuable information for antigenic evolution and immunogenicity analysis in vaccine candidate selection. Together, our study assessed the potency of pseudovirus systems in vaccine efficacy, antigenic analysis, and immunogenicity in the vaccine development of emerging and re-emerging viruses. CONCLUSION: Instead of handling live highly pathogenic viruses in a high biosafety level facility, using pseudovirus systems would speed up the process of vaccine development to provide community protection against emerging and re-emerging viral diseases with high pathogenicity.


Asunto(s)
Betacoronavirus/efectos de los fármacos , Infecciones por Coronavirus/tratamiento farmacológico , Gripe Aviar/tratamiento farmacológico , Neumonía Viral/tratamiento farmacológico , Vacunas Virales , Animales , Betacoronavirus/inmunología , Betacoronavirus/patogenicidad , Aves , Infecciones por Coronavirus/prevención & control , Desarrollo de Medicamentos/métodos , Humanos , Virus de la Influenza A/inmunología , Gripe Aviar/prevención & control , Gripe Aviar/virología , Pandemias/prevención & control , Neumonía Viral/prevención & control
5.
J Vet Sci ; 21(3): e34, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32476310

RESUMEN

BACKGROUND: A nationwide outbreak of foot-and-mouth disease (FMD) in South Korea caused massive economic losses in 2010. Since then, the Animal and Plant Quarantine Agency (QIA) has enhanced disinfection systems regarding livestock to prevent horizontal transmission of FMD and Avian influenza (AI). Although the amount of disinfectant used continues to increase, cases of FMD and AI have been occurring annually in Korea, except 2012 and 2013. OBJECTIVES: This study measured the concentration of the disinfectant to determine why it failed to remove the horizontal transmission despite increased disinfectant use. METHODS: Surveys were conducted from February to May 2017, collecting 348 samples from disinfection systems. The samples were analyzed using the Standards of Animal Health Products analysis methods from QIA. RESULTS: Twenty-three facilities used inappropriate or non-approved disinfectants. Nearly all sampled livestock farms and facilities-93.9%-did not properly adjust the disinfectant concentration. The percentage using low concentrations, or where no effective substance was detected, was 46.9%. Furthermore, 13 samples from the official disinfection station did not use effective disinfectant, and-among 72 samples from the disinfection station-88.89% were considered inappropriate concentration, according to the foot-and-mouth disease virus guidelines; considering the AIV guideline, 73.61% were inappropriate concentrations. Inappropriate concentration samples on automatic (90.00%) and semi-automatic (90.90%) disinfection systems showed no significant difference from manual methods (88.24%). Despite this study being conducted during the crisis level, most disinfectants were used inappropriately. CONCLUSIONS: This may partially explain why horizontal transmission of FMD and AI cannot be effectively prevented despite extensive disinfectant use.


Asunto(s)
Enfermedades de los Bovinos , Brotes de Enfermedades/veterinaria , Desinfectantes/farmacología , Fiebre Aftosa , Gripe Aviar , Enfermedades de las Aves de Corral , Enfermedades de los Porcinos , Animales , Bovinos , Enfermedades de los Bovinos/epidemiología , Enfermedades de los Bovinos/prevención & control , Enfermedades de los Bovinos/transmisión , Enfermedades de los Bovinos/virología , Pollos , Brotes de Enfermedades/prevención & control , Patos , Fiebre Aftosa/epidemiología , Fiebre Aftosa/prevención & control , Fiebre Aftosa/transmisión , Fiebre Aftosa/virología , Virus de la Fiebre Aftosa/efectos de los fármacos , Virus de la Influenza A/efectos de los fármacos , Gripe Aviar/epidemiología , Gripe Aviar/prevención & control , Gripe Aviar/transmisión , Gripe Aviar/virología , Ganado , Enfermedades de las Aves de Corral/epidemiología , Enfermedades de las Aves de Corral/prevención & control , Enfermedades de las Aves de Corral/transmisión , Enfermedades de las Aves de Corral/virología , República de Corea/epidemiología , Sus scrofa , Porcinos , Enfermedades de los Porcinos/epidemiología , Enfermedades de los Porcinos/prevención & control , Enfermedades de los Porcinos/transmisión , Enfermedades de los Porcinos/virología
6.
Rev Esp Salud Publica ; 942020 Mar 31.
Artículo en Español | MEDLINE | ID: mdl-32381999

RESUMEN

Wild waterfowl are considered the main natural reservoir of influenza viruses and they have contributed to the reassortment of both pandemic viruses and viruses responsible for outbreaks of avian influenza in wild and domestic species. In order to determinate the factors involved, we reviewed the human cases of avian influenza related to the management of wild birds, the use of personal protective equipment, as well as the basis of surveillance programs of highly pathogenic avian influenza in wild birds in Spain. The direct transmission of influenza virus from wild birds to humans is a rare event. However, our epidemiological context is influenced by climate change and marked by the presence of migratory routes from territories where infection may be present. Thus and due to the clinical, economical and public health implications that such infections may have, the different groups exposed to wild birds (veterinarians, biologists, ornithologists, conservationists, field technicians, environmental officers, falconers, hunters, etc.) should know which are the possible sources of infection and how to handle the personal protective equipment. Besides, it is important that those groups know the current sanitary situation regarding avian influenza so they can consequently adapt their activities and employ proper protective measures, in addition to providing valuable information for surveillance programs.


Asunto(s)
Animales Salvajes/virología , Aves/virología , Gripe Aviar/transmisión , Gripe Humana/transmisión , Enfermedades Profesionales , Exposición Profesional/estadística & datos numéricos , Zoonosis/transmisión , Animales , Reservorios de Enfermedades/virología , Humanos , Gripe Aviar/epidemiología , Gripe Aviar/prevención & control , Gripe Humana/epidemiología , Gripe Humana/prevención & control , Enfermedades Profesionales/epidemiología , Enfermedades Profesionales/prevención & control , Exposición Profesional/efectos adversos , Exposición Profesional/prevención & control , Equipo de Protección Personal , Vigilancia en Salud Pública , España , Zoonosis/epidemiología , Zoonosis/prevención & control
7.
Arch Razi Inst ; 75(1): 9-16, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-32291997

RESUMEN

Avian influenza virus (AIV) H9N2 is endemic in Iran and its large-scale circulation in the poultry industry of the country is devastating. This virus was first reported in the industrial poultry populations of Iran in July 1998. Some of the published studies showed that inactivated avian influenza (AI) vaccines are capable of inducing an immune response and providing protection against morbidity and mortality in different countries (Vasfi et al., 2002; Tavakkoli et al., 2011). Low pathogenicity avian influenza subtype H9N2 virus has been reported to have a zoonotic potential and widespread distribution in Iran. Therefore, water-in-oil emulsion vaccines are employed to control the disease in chickens (Nili and Asasi, 2003). This cohort study was conducted during July 2016-November 2017 in broiler chicken farms of Qazvin province, Iran to investigate the serological change trends in broiler chickens in this region. Level of immunity against the H9N2 virus was evaluated by hemagglutination inhibition assay. Fifteen farms out of thirty enrolled units used AI H9N2 killed vaccines. The minimum of mean antibody titers (MATs) was 4.54-2.42 and the maximum of MATs was 4.54+2.42 on day 3. In addition, the minimum and maximum MATs on day 50 were 0.4-0.64 and 0.4+0.064, respectively. The transfer rate of H9N2 AIV antibodies from the serum of breeders to the serum of chickens was calculated as 60.35% in our study. A significant difference was revealed between the maternal mean antibody titers (MMATs) and the MATs on day 3 (P<0.001). In addition, the difference between the MATs on day 3 and the MATs on day 10 was found to be significant (P<0.01). Moreover, MATs were significantly different between the vaccinated and unvaccinated herds on day 40 (P<0.05), while no significant difference was observed on days 3, 10, 20, and 30 (P>0.05). According to the results of this study, antibody titers in the vaccinated farms did not reach the protective level until the end of the rearing period. Most of the unvaccinated herds experienced a spurt in antibody titers due to exposure to the virus. Consequently, biosecurity measures must be implemented more seriously and strictly in broiler farms.


Asunto(s)
Pollos , Subtipo H9N2 del Virus de la Influenza A/inmunología , Vacunas contra la Influenza/inmunología , Gripe Aviar/prevención & control , Enfermedades de las Aves de Corral/prevención & control , Animales , Estudios de Cohortes , Vacunas contra la Influenza/administración & dosificación , Gripe Aviar/virología , Irán , Enfermedades de las Aves de Corral/virología , Vacunas de Productos Inactivados/administración & dosificación , Vacunas de Productos Inactivados/inmunología
8.
Vet Microbiol ; 243: 108640, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32273019

RESUMEN

In the present study, we have generated several H5N2 HA recombinant baculoviruses for production of a HA subunit vaccine against the lethal H5N2 avian influenza virus (AIV). The effective display of functional HA on the cell membrane and baculoviral envelope was examined. Our results reveal that chickens immunized with the chimeric AIV HA protein fused with the baculovirus gp64 cytoplasmic domain (CTD) induced higher HI titer. To further increase the expression level of the H5N2 AIV HA protein, the HA gene of H5N2 AIV was amplified and cloned into three novel baculovirus surface display vectors BacDual DisplayEGFP-2HA, BacDual DisplayEGFP-3HA, BacDual DisplayEGFP-4HA which contains multiple expression cassettes for higher level display of HA proteins on the cell membrane and baculovirus envelope. To determine the optimum conditions for producing HA protein, various MOI, infection times, and shaker times for virus transfection were tested. Our results reveal that the conditions of an MOI of 5, 3 day post infection, and 15 min of shaker time have higher efficiency for HA protein production. Our results reveal that the baculovirus surface display vector pBacDual DisplayEGFP-4HA increases significantly the expression level of the H5N2 AIV HA protein. Chickens that received two doses of BacDual DisplayEGFP-4HA cell lysates formulated with Montanide ISA70 adjuvant elicited efficient immunogenicity and had an average HI titer of 7 log2 at 2 weeks post-vaccination. Challenge studies revealed that vaccinated chickens with HI titers 5 log2 were completely protected against the lethal H5N1 AIV challenge. Furthermore, HI titers could be maintained at 5 log2 for 20 weeks for laying hens. This study suggests that the HA protein expression from the baculovirus surface display system could be a safe and efficacious subunit vaccine for chickens.


Asunto(s)
Baculoviridae/genética , Glicoproteínas Hemaglutininas del Virus de la Influenza/genética , Glicoproteínas Hemaglutininas del Virus de la Influenza/inmunología , Subtipo H5N1 del Virus de la Influenza A/patogenicidad , Vacunas contra la Influenza/inmunología , Gripe Aviar/prevención & control , Animales , Anticuerpos Antivirales/sangre , Pollos/inmunología , Pollos/virología , Femenino , Subtipo H5N2 del Virus de la Influenza A/genética , Vacunas contra la Influenza/genética , Gripe Aviar/inmunología , Vacunas de Subunidad/genética , Vacunas de Subunidad/inmunología
9.
Sci Rep ; 10(1): 2221, 2020 02 10.
Artículo en Inglés | MEDLINE | ID: mdl-32042001

RESUMEN

Highly pathogenic avian influenza (HPAI) is a devastating disease of poultry and a serious threat to public health. Vaccination with inactivated virus vaccines has been applied for several years as one of the major policies to control highly pathogenic avian influenza virus (HPAIV) infections in chickens. Viral-vectored HA protein vaccines are a desirable alternative for inactivated vaccines. However, each viral vector possesses its own advantages and disadvantages for the development of a HA-based vaccine against HPAIV. Recombinant Newcastle disease virus (rNDV) strain LaSota expressing HA protein vaccine has shown promising results against HPAIV; however, its replication is restricted only to the respiratory tract. Therefore, we thought to evaluate avian paramyxovirus serotype 3 (APMV-3) strain Netherlands as a safe vaccine vector against HPAIV, which has high efficiency replication in a greater range of host organs. In this study, we generated rAPMV-3 expressing the HA protein of H5N1 HPAIV using reverse genetics and evaluated the induction of neutralizing antibodies and protection by rAPMV3 and rNDV expressing the HA protein against HPAIV challenge in chickens. Our results showed that immunization of chickens with rAPMV-3 or rNDV expressing HA protein provided complete protection against HPAIV challenge. However, immunization of chickens with rAPMV-3 expressing HA protein induced higher level of neutralizing antibodies compared to that of rNDV expressing HA protein. These results suggest that a rAPMV-3 expressing HA protein might be a better vaccine for mass-vaccination of commercial chickens in field conditions.


Asunto(s)
Avulavirus/inmunología , Glicoproteínas Hemaglutininas del Virus de la Influenza/inmunología , Subtipo H5N1 del Virus de la Influenza A/patogenicidad , Vacunas contra la Influenza/inmunología , Gripe Aviar/prevención & control , Crianza de Animales Domésticos , Animales , Anticuerpos Neutralizantes/análisis , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/análisis , Anticuerpos Antivirales/inmunología , Avulavirus/genética , Pollos , Vectores Genéticos/genética , Vectores Genéticos/inmunología , Inmunogenicidad Vacunal , Vacunas contra la Influenza/administración & dosificación , Vacunas contra la Influenza/genética , Gripe Aviar/virología , Vacunas Sintéticas/administración & dosificación , Vacunas Sintéticas/genética , Vacunas Sintéticas/inmunología
10.
Transbound Emerg Dis ; 67(4): 1463-1471, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32065513

RESUMEN

In recent decades, multiple subtypes (i.e. H9N2, H5N1 and H7N9) of avian influenza virus (AIV) have become widespread in China, which has caused enormous economic losses and posed considerable threats to public health. In this review, with the aim to provide insights into and guidelines for the control of AIV spread in China and globally in the future, we analysed the reasons why AIV has persisted in China based on socio-economic features, including poultry biosecurity, live bird markets, live bird transportation, wild birds, poultry waterfowl, poultry density, poultry population and infected birds. We also described the present status of the AIV subtypes H9, H5 and H7 in China to elucidate the effectiveness of the strategies currently employed in China (i.e. culling, mass vaccination and biosecurity improvement) to control the disease based on a literature review and our unpublished surveillance data collected over a 12-year period from 2007 to 2018. We then summarized the lessons to be learned from the control experience in China, including whether culling of infected birds is of limited value for disease control and whether improved biosecurity is a better option than culling and vaccination for the long-term control of AIV, and when the vaccine strain should be updated.


Asunto(s)
Brotes de Enfermedades/veterinaria , Subtipo H5N1 del Virus de la Influenza A/inmunología , Subtipo H7N9 del Virus de la Influenza A/inmunología , Subtipo H9N2 del Virus de la Influenza A/inmunología , Gripe Aviar/prevención & control , Vacunación Masiva/veterinaria , Sacrificio de Animales , Animales , Aves , China/epidemiología , Guías como Asunto , Gripe Aviar/epidemiología , Gripe Aviar/virología , Aves de Corral
11.
J Infect Dis ; 221(4): 553-560, 2020 02 03.
Artículo en Inglés | MEDLINE | ID: mdl-31323094

RESUMEN

BACKGROUND: This review aimed to provide constructive suggestions for the control and management of avian influenza through quantitative and qualitative evaluation of the impact of different live poultry market (LPM) interventions. METHODS: Both English and Chinese language databases were searched for articles that were published on or before 9 November 2018. After extraction and assessment of the included literature, Stata14.0 was applied to perform a meta-analysis to explore the impacts of LPM interventions. RESULTS: A total of 19 studies were identified. In total, 224 human, 3550 poultry, and 13 773 environment samples were collected before the intervention; 181 people, 4519 poultry, and 9562 environments were sampled after LPM interventions. Avian influenza virus (AIV) detection rates in the LPM environment (odds ratio [OR], 0.393; 95% confidence interval [CI], 0.262-0.589) and the incidence of AIV infection (OR, 0.045; 95% CI, 0.025-0.079) were significantly lower after LPM interventions, while interventions were not significantly effective in reducing AIV detection in poultry samples (OR, 0.803; 95% CI, 0.403-1.597). CONCLUSIONS: LPM interventions can reduce AIV human infections and the detection rate of AIV in market environments.


Asunto(s)
Virus de la Influenza A , Gripe Aviar/epidemiología , Gripe Aviar/prevención & control , Gripe Humana/epidemiología , Gripe Humana/prevención & control , Enfermedades de las Aves de Corral/epidemiología , Enfermedades de las Aves de Corral/prevención & control , Animales , Desinfección/métodos , Humanos , Incidencia , Gripe Aviar/transmisión , Aves de Corral/virología , Enfermedades de las Aves de Corral/transmisión , Enfermedades de las Aves de Corral/virología , Cuarentena/métodos
12.
Transbound Emerg Dis ; 67(2): 661-677, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31587498

RESUMEN

Free-range poultry farms have a high risk of introduction of avian influenza viruses (AIV), and it is presumed that wild (water) birds are the source of introduction. There is very scarce quantitative data on wild fauna visiting free-range poultry farms. We quantified visits of wild fauna to a free-range area of a layer farm, situated in an AIV hot-spot area, assessed by video-camera monitoring. A total of 5,016 hr (209 days) of video recordings, covering all 12 months of a year, were analysed. A total of 16 families of wild birds and five families of mammals visited the free-range area of the layer farm. Wild birds, except for the dabbling ducks, visited the free-range area almost exclusively in the period between sunrise and the moment the chickens entered the free-range area. Known carriers of AIV visited the outdoor facility regularly: species of gulls almost daily in the period January-August; dabbling ducks only in the night in the period November-May, with a distinct peak in the period December-February. Only a small fraction of visits of wild fauna had overlap with the presence of chickens at the same time in the free-range area. No direct contact between chickens and wild birds was observed. It is hypothesized that AIV transmission to poultry on free-range poultry farms will predominantly take place via indirect contact: taking up AIV by chickens via wild-bird-faeces-contaminated water or soil in the free-range area. The free-range poultry farmer has several possibilities to potentially lower the attractiveness of the free-range area for wild (bird) fauna: daily inspection of the free-range area and removal of carcasses and eggs; prevention of forming of water pools in the free-range facility. Furthermore, there are ways to scare-off wild birds, for example use of laser equipment or trained dogs.


Asunto(s)
Pollos/virología , Virus de la Influenza A/fisiología , Gripe Aviar/transmisión , Enfermedades de las Aves de Corral/transmisión , Animales , Animales Salvajes , Aves , Charadriiformes , Patos , Granjas , Femenino , Gripe Aviar/prevención & control , Gripe Aviar/virología , Países Bajos , Aves de Corral , Enfermedades de las Aves de Corral/prevención & control , Enfermedades de las Aves de Corral/virología , Grabación en Video
13.
Influenza Other Respir Viruses ; 14(2): 215-225, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31659871

RESUMEN

A major lesson learned from the public health response to the 2009 H1N1 pandemic was the need to shorten the vaccine delivery timeline to achieve the best pandemic mitigation results. A gap analysis of previous pre-pandemic vaccine development activities identified possible changes in the Select Agent exclusion process that would maintain safety and shorten the timeline to develop candidate vaccine viruses (CVVs) for use in pandemic vaccine manufacture. Here, we review the biosafety characteristics of CVVs developed in the past 15 years to support a shortened preparedness timeline for A(H5) and A(H7) subtype highly pathogenic avian influenza (HPAI) CVVs. Extensive biosafety experimental evidence supported recent changes in the implementation of Select Agent regulations that eliminated the mandatory chicken pathotype testing requirements and expedited distribution of CVVs to shorten pre-pandemic and pandemic vaccine manufacturing by up to 3 weeks.


Asunto(s)
Contención de Riesgos Biológicos , Medición de Riesgo , Vacunas Virales/biosíntesis , Animales , Aves , Humanos , Subtipo H5N1 del Virus de la Influenza A/inmunología , Subtipo H7N9 del Virus de la Influenza A/inmunología , Gripe Aviar/epidemiología , Gripe Aviar/inmunología , Gripe Aviar/prevención & control , Gripe Humana/epidemiología , Gripe Humana/inmunología , Gripe Humana/prevención & control , Pandemias/prevención & control , Aves de Corral/virología , Cultivo de Virus/métodos , Zoonosis/epidemiología , Zoonosis/inmunología , Zoonosis/prevención & control
14.
Avian Pathol ; 49(2): 161-170, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31738584

RESUMEN

The H5N1 subtype of highly pathogenic avian influenza virus has been circulating in poultry in Indonesia since 2003 and vaccination has been used as a strategy to eradicate the disease. However, monitoring of vaccinated poultry flocks for H5N1 infection by serological means has been difficult, as vaccine antibodies are not readily distinguishable from those induced by field viruses. Therefore, a test that differentiates infected and vaccinated animals (DIVA) would be essential. Currently, no simple and specific DIVA test is available for screening of a large number of vaccinated chickens. Several epitopes on E29 domain of the haemagglutinin H5N1 subunit 2 (HA2) have recently been examined for their antigenicity and potential as possible markers for DIVA in chicken. In this study, the potential of E29 as an antigen for DIVA was evaluated in detail. Three different forms of full-length E29 peptide, a truncated E29 peptide (E15), and a recombinant E29 were compared for their ability to detect anti-E29 antibodies. Preliminary ELISA experiments using mono-specific chicken and rabbit E29 sera, and a mouse monoclonal antibody revealed that the linear E29 peptide was the most antigenic. Further examination of the E29 antigenicity in ELISA, using several sera from experimentally infected or vaccinated chickens, revealed that the full-length E29 peptide had the greatest discrimination power between infected and vaccinated chicken sera while providing the least non-specific reaction. This study demonstrates the usefulness of the HPAI H5N1 HA2 E29 epitope as a DIVA antigen in HPAI H5N1-vaccinated and -infected chickens.RESEARCH HIGHLIGHTS E29 (HA2 positions 488-516) epitope is antigenic in chickens.Antibodies to E29 are elicited following live H5N1 virus infection in chickens.E29 epitope is a potential DIVA antigen for use in ELISA.


Asunto(s)
Anticuerpos Antivirales/sangre , Epítopos/inmunología , Hemaglutininas Virales/inmunología , Subtipo H5N1 del Virus de la Influenza A/inmunología , Vacunas contra la Influenza/inmunología , Gripe Aviar/prevención & control , Animales , Anticuerpos Antivirales/inmunología , Antígenos Virales , Pollos , Hemaglutininas Virales/química , Gripe Aviar/diagnóstico , Gripe Aviar/virología , Subunidades de Proteína , Vacunación
15.
Avian Pathol ; 49(1): 21-28, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31412705

RESUMEN

Since the emergence of low pathogenic avian influenza (LPAI) H9N2 viruses in Morocco in 2016, severe respiratory problems have been encountered in the field. Infectious bronchitis virus (IBV) is often detected together with H9N2, suggesting disease exacerbation in cases of co-infections. This hypothesis was therefore tested and confirmed in laboratory conditions using specific-pathogen-free chickens. Most common field vaccine programmes were then tested to compare their efficacies against these two co-infecting agents. IBV γCoV/chicken/Morocco/I38/2014 (Mor-IT02) and LPAI virus A/chicken/Morocco/SF1/2016 (Mor-H9N2) were thus inoculated to commercial chickens. We showed that vaccination with two heterologous IBV vaccines (H120 at day one and 4/91 at day 14 of age) reduced the severity of clinical signs as well as macroscopic lesions after simultaneous experimental challenge. In addition, LPAI H9N2 vaccination was more efficient at day 7 than at day 1 in limiting disease post simultaneous challenge.RESEARCH HIGHLIGHTS Simultaneous challenge with IBV and AIV H9N2 induced higher pathogenicity in SPF birds than inoculation with IBV or AIV H9N2 alone.Recommended vaccination programme in commercial broilers to counter Mor-IT02 IBV and LPAIV H9N2 simultaneous infections: IB live vaccine H120 (d1), AIV H9N2 inactivated vaccine (d7), IB live vaccine 4-91 (d14).


Asunto(s)
Pollos , Coinfección/veterinaria , Infecciones por Coronavirus/veterinaria , Virus de la Bronquitis Infecciosa , Subtipo H9N2 del Virus de la Influenza A , Gripe Aviar/virología , Animales , Anticuerpos Antivirales/sangre , Embrión de Pollo , Coinfección/prevención & control , Coinfección/virología , Infecciones por Coronavirus/prevención & control , Infecciones por Coronavirus/virología , Gripe Aviar/prevención & control , Pulmón/patología , Marruecos , Orofaringe/virología , Proyectos Piloto , Enfermedades de las Aves de Corral/prevención & control , Enfermedades de las Aves de Corral/virología , ARN Viral/química , ARN Viral/aislamiento & purificación , Reacción en Cadena en Tiempo Real de la Polimerasa/veterinaria , Organismos Libres de Patógenos Específicos , Tráquea/patología , Vacunación/veterinaria , Vacunas Atenuadas , Vacunas Virales , Esparcimiento de Virus
16.
Avian Dis ; 63(4): 606-618, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31865675

RESUMEN

Infectious bursal disease (IBD) virus (IBDV) is the causative agent of a highly contagious and immunosuppressive disease of chickens with huge economic losses to the poultry industry despite extensive vaccination. Analysis of isolated IBDV field strains from vaccinated birds would greatly improve the current immunization regimens and support the development of vaccines that offer better immunity. The study investigated the genetic characteristics and pathologic features of IBDVs in commercial broiler chicken farms, as well as the effect of IBDV infection on the efficacy of vaccination against avian influenza virus (AIV) and Newcastle disease virus (NDV) under field conditions. A preliminary diagnosis of IBD was made on the basis of the flock history and the characteristic gross pathologic findings. Microscopically, lymphoid depletion in bursal follicles with infiltration of lymphomononuclear cells along with cystic cavitations reflected the IBDV infection. The molecular analysis confirmed the IBDV infection in (57.1%) of tested flocks. Upon phylogenetic analysis of the VP2 hypervariable region of 14 Egyptian IBDVs, most viruses (n = 12) were clustered within the genogroup 3, while two viruses were closely related to attenuated vaccine isolates in genogroup 1. The analysis of the amino acid (aa) sequences revealed that most of the strains possessed five consistent aas at the VP2 protein (222A, 242I, 256I, 294I, and 299S), which are characteristic for the very virulent IBDV (vvIBDV). Serology indicated the immunosuppressive effect of IBDV, which is represented by a decrease (1.6-2.6 and 1.4-2.6 mean log 2) in the hemagglutination inhibition titer of the low pathogenic AIV subtype H9N2 and NDV, respectively. The examined IBDVs showed a high mutation rate within the hypervariable domain of the VP2 peptide. The results highlighted the need for carrying out an inclusive surveillance of IBDV infections in chicken flocks in Egypt.


Asunto(s)
Pollos , Virus de la Enfermedad Infecciosa de la Bolsa/inmunología , Virus de la Influenza A/inmunología , Virus de la Enfermedad de Newcastle/inmunología , Enfermedades de las Aves de Corral/prevención & control , Vacunas Virales/inmunología , Animales , Infecciones por Birnaviridae/epidemiología , Infecciones por Birnaviridae/inmunología , Infecciones por Birnaviridae/prevención & control , Infecciones por Birnaviridae/veterinaria , Cicer , Egipto/epidemiología , Virus de la Enfermedad Infecciosa de la Bolsa/clasificación , Vacunas contra la Influenza/inmunología , Gripe Aviar/epidemiología , Gripe Aviar/inmunología , Gripe Aviar/prevención & control , Epidemiología Molecular , Enfermedad de Newcastle/epidemiología , Enfermedad de Newcastle/inmunología , Enfermedad de Newcastle/prevención & control , Enfermedades de las Aves de Corral/epidemiología , Enfermedades de las Aves de Corral/inmunología , Prevalencia , Vacunación/veterinaria
17.
Avian Dis ; 63(sp1): 219-229, 2019 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-31713400

RESUMEN

In late 2016, a highly pathogenic avian influenza (HPAI) virus subtype H5N8 clade 2.3.4.4 was reported in Egypt in migratory birds; subsequently, the virus spread to backyard and commercial poultry in several Egyptian governorates, causing severe economic losses to the poultry industry. Here, a recombinant subunit commercial H5 vaccine prepared from the clade 2.3.2 H5 segment on baculovirus was evaluated in Pekin ducks (Anasplatyrhynchos domesticus) and Muscovy ducks (Cairina moschata) in Biosafety Level 3 isolators by using two vaccination regimes: either a single dose on day 10 and a challenge on day 31 or a double dose on days 10 and 28 and a challenge on day 49. The protection parameters were evaluated after experimental infection with the Egyptian HPAI H5N8 isolate clade 2.3.4.4b (A/common-coot/Egypt/CA285/2016) based on mortality rate, clinical signs, gross lesions, seroconversion, virus shedding, and histopathologic changes. In the single-dose vaccination regime, the mortality rate in Muscovy and Pekin ducks was 10% and 0% vs. 40% and 0% in nonvaccinated challenged ducks, respectively. In the double-dose vaccination regime, the mortality rates in Muscovy and Pekin ducks were 0% and 0% vs. 60% and 40% in nonvaccinated challenged ducks, respectively. Muscovy ducks developed more severe clinical signs and gross lesions than Pekin ducks. In addition, tracheal viral shedding in challenged Muscovy ducks, in the single-dose vaccination regime, was 50%, 22%, and 0% at 3, 5, and 7 days postchallenge (DPC), respectively, and was 0% in all Pekin ducks vs. 100% in all challenged nonvaccinated Muscovy and Pekin ducks at 3, 5, and 7 DPC. The viral shedding in challenged Muscovy and Pekin ducks, in the double-dose vaccination regime, was 0% at 3, 5, and 7 DPC vs. 100% in nonvaccinated challenged Muscovy and Pekin ducks, respectively. The results of this study indicate that the H5 baculovirus-based vaccine can be used in ducks with better vaccination regime based on double-dose vaccination at 10 and 28 days of age. In addition, they highlight the need to evaluate the efficacy of currently used commercial vaccines against challenge with the newly emerged HPAI H5N8 clade 2.3.4.4 in the field in Egypt to ensure proper control strategy in ducks.


Asunto(s)
Patos , Subtipo H5N8 del Virus de la Influenza A/efectos de los fármacos , Gripe Aviar/prevención & control , Enfermedades de las Aves de Corral/prevención & control , Vacunas Virales/farmacología , Animales , Baculoviridae , Vacunas Sintéticas/farmacología
18.
Cell Host Microbe ; 26(6): 715-728.e8, 2019 12 11.
Artículo en Inglés | MEDLINE | ID: mdl-31757769

RESUMEN

H7N9 avian influenza virus causes severe infections and might have the potential to trigger a major pandemic. Molecular determinants of human humoral immune response to N9 neuraminidase (NA) proteins, which exhibit unusual features compared with seasonal influenza virus NA proteins, are ill-defined. We isolated 35 human monoclonal antibodies (mAbs) from two H7N9 survivors and two vaccinees. These mAbs react to NA in a subtype-specific manner and recognize diverse antigenic sites on the surface of N9 NA, including epitopes overlapping with, or distinct from, the enzyme active site. Despite recognizing multiple antigenic sites, the mAbs use a common mechanism of action by blocking egress of nascent virions from infected cells, thereby providing an antiviral prophylactic and therapeutic protection in vivo in mice. Studies of breadth, potency, and diversity of antigenic recognition from four subjects suggest that vaccination with inactivated adjuvanted vaccine induce NA-reactive responses comparable to that of H7N9 natural infection.


Asunto(s)
Anticuerpos Neutralizantes , Subtipo H7N9 del Virus de la Influenza A/inmunología , Neuraminidasa/inmunología , Infecciones por Orthomyxoviridae , Liberación del Virus/efectos de los fármacos , Animales , Anticuerpos Heterófilos/farmacología , Anticuerpos Monoclonales/farmacología , Anticuerpos Neutralizantes/farmacología , Anticuerpos Antivirales/farmacología , Aves , Epítopos/inmunología , Humanos , Subtipo H7N9 del Virus de la Influenza A/efectos de los fármacos , Vacunas contra la Influenza/inmunología , Gripe Aviar/prevención & control , Gripe Aviar/virología , Gripe Humana/prevención & control , Gripe Humana/virología , Ratones , Infecciones por Orthomyxoviridae/prevención & control , Infecciones por Orthomyxoviridae/virología , Profilaxis Pre-Exposición , Vacunación , Vacunas de Productos Inactivados , Proteínas Virales/inmunología
19.
Rev Sci Tech ; 38(1): 225-237, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-31564728

RESUMEN

In 2016-2017, the H5N8 strain of highly pathogenic avian influenza (HPAI) spread worldwide and Uganda reported the first occurrence of the disease in its poultry and wild birds. Genetic analysis revealed that the virus clusters with 2.3.4.4 group B strains from birds in central and southern Asia, and thus forms part of the 2.3.4.4 group B clade. Since Uganda is in the path of two major migratory bird flyways, it is likely that infected migratory wild birds played a crucial role in the introduction of H5N8 HPAI viruses into Uganda. The outbreaks happened in the districts of Wakiso, Masaka and Kalangala and affected domestic and wild birds. A One Health Multisectoral Coordination Committee, consisting of a National Task Force, Technical Working Groups and District Disaster Management Committees, was immediately activated to coordinate the preparedness and response efforts to control the disease. In all the affected districts, surveillance was intensified on both domestic and wild birds; biosecurity measures were increased; and movement controls, culling, cleaning, disinfection and safe disposal of carcasses were implemented. Awareness of the disease was raised through education materials, leaflets and brochures distributed to farmers. Finally, Uganda successfully controlled the H5N8 outbreak, using its national preparedness and response mechanisms and through collaboration with international partners. The emergence and spread of this virus strain in Uganda and other parts of Africa poses a significant threat to the poultry industry and food security.


Asunto(s)
Animales Salvajes , Brotes de Enfermedades , Subtipo H5N8 del Virus de la Influenza A , Gripe Aviar , Migración Animal , Animales , Asia , Aves , Brotes de Enfermedades/prevención & control , Humanos , Gripe Aviar/prevención & control , Uganda
20.
Int J Nanomedicine ; 14: 7533-7548, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31571862

RESUMEN

Background: The influenza A virus (IAV) is known for its high variability and poses a huge threat to the health of humans and animals. Pigs play a central role in the cross-species reassortment of IAV. Ectodomain of matrix protein 2 (M2e) is the most conserved protective antigen in IAV and can be used to develop nanovaccines through nanoparticles displaying to increase its immunogenicity. However, the high immunogenicity of nanoparticles can cause the risk of off-target immune response, and excess unwanted antibodies may interfere with the protective efficacy of M2e-specific antibodies. Therefore, it is necessary to select reasonable nanoparticles to make full use of antibodies against nanoparticles while increasing the level of M2e-specific antibodies. Porcine circovirus type 2 (PCV2) is the most susceptible virus in pigs and can promote IAV infection. It is meaningful to develop a vaccine that can simultaneously control swine influenza virus (SIV) and PCV2. Methods: In the present study, M2e of different copy numbers were inserted into the capsid (Cap) protein of PCV2 and expressed in Escherichia coli to form self-assembled chimeric virus-like particles (VLPs) nanovaccine. BALB/c mice and pigs were immunized with these nanovaccines to explore optimal anti-IAV and anti-PCV2 immunity. Results: Cap is capable of carrying at least 81 amino acid residues (three copies of M2e) at its C-terminal without impairing VLPs formation. Cap-3M2e VLPs induced the highest levels of M2e-specific immune responses, conferring protection against lethal challenge of IAVs from different species and induced specific immune responses consistent with PCV2 commercial vaccines in mice. In addition, Cap-3M2e VLPs induced high levels of M2e-specific antibodies and PCV2-specific neutralizing antibodies in pigs. Conclusion: Cap-3M2e VLP is an economical and promising bivalent nanovaccine, which provides dual protection against IAV and PCV2.


Asunto(s)
Circovirus/inmunología , Virus de la Influenza A/inmunología , Nanopartículas/uso terapéutico , Infecciones por Orthomyxoviridae/inmunología , Infecciones por Orthomyxoviridae/prevención & control , Vacunas Virales/inmunología , Animales , Anticuerpos Antivirales/inmunología , Formación de Anticuerpos/inmunología , Especificidad de Anticuerpos/inmunología , Aves/virología , Proteínas de la Cápside/química , Proliferación Celular , Citocinas/metabolismo , Perros , Femenino , Humanos , Inmunidad Humoral , Gripe Aviar/inmunología , Gripe Aviar/prevención & control , Gripe Aviar/virología , Gripe Humana/inmunología , Gripe Humana/prevención & control , Gripe Humana/virología , Linfocitos/citología , Células de Riñón Canino Madin Darby , Ratones Endogámicos BALB C , Pruebas de Neutralización , Proteínas Recombinantes/aislamiento & purificación , Porcinos , Virión/inmunología , Virión/ultraestructura
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA