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Low ZY, Wong KH, Wen Yip AJ, Choo WS. The convergent evolution of influenza A virus: Implications, therapeutic strategies and what we need to know. CURRENT RESEARCH IN MICROBIAL SCIENCES 2023; 5:100202. [PMID: 37700857 PMCID: PMC10493511 DOI: 10.1016/j.crmicr.2023.100202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/14/2023] Open
Abstract
Influenza virus infection, more commonly known as the 'cold flu', is an etiological agent that gives rise to recurrent annual flu and many pandemics. Dated back to the 1918- Spanish Flu, the influenza infection has caused the loss of many human lives and significantly impacted the economy and daily lives. Influenza virus can be classified into four different genera: influenza A-D, with the former two, influenza A and B, relevant to humans. The capacity of antigenic drift and shift in Influenza A has given rise to many novel variants, rendering vaccines and antiviral therapies useless. In light of the emergence of a novel betacoronavirus, the SARS-CoV-2, unravelling the underpinning mechanisms that support the recurrent influenza epidemics and pandemics is essential. Given the symptom similarities between influenza and covid infection, it is crucial to reiterate what we know about the influenza infection. This review aims to describe the origin and evolution of influenza infection. Apart from that, the risk factors entail the implication of co-infections, especially regarding the COVID-19 pandemic is further discussed. In addition, antiviral strategies, including the potential of drug repositioning, are discussed in this context. The diagnostic approach is also critically discussed in an effort to understand better and prepare for upcoming variants and potential influenza pandemics in the future. Lastly, this review encapsulates the challenges in curbing the influenza spread and provides insights for future directions in influenza management.
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Affiliation(s)
- Zheng Yao Low
- School of Science, Monash University Malaysia, 47500 Subang Jaya, Selangor, Malaysia
| | - Ka Heng Wong
- School of Science, Monash University Malaysia, 47500 Subang Jaya, Selangor, Malaysia
| | - Ashley Jia Wen Yip
- School of Science, Monash University Malaysia, 47500 Subang Jaya, Selangor, Malaysia
| | - Wee Sim Choo
- School of Science, Monash University Malaysia, 47500 Subang Jaya, Selangor, Malaysia
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2
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Kareche H, Daly JM, Laabassi F. Epidemiology of equine influenza in the Maghreb area. Comp Immunol Microbiol Infect Dis 2022; 89:101868. [PMID: 36087448 DOI: 10.1016/j.cimid.2022.101868] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Revised: 08/21/2022] [Accepted: 08/24/2022] [Indexed: 10/14/2022]
Abstract
Equine influenza (EI) is one of the most contagious respiratory infections in horses, donkeys and mules, caused by equine influenza A virus (EIV). It remains a disease with a strong economic stake for the equine industry. This review focuses on the epidemiological situation of EIV in the Maghreb area, which includes Algeria, Morocco and Tunisia. There is serological evidence for extensive circulation of EIV in the Maghreb area since the early 1970s, but reports of detailed investigation of outbreaks are scarce with no documented isolation or molecular characterization of EIV from Tunisia. Isolates of EIV were obtained from outbreaks in Algeria in 1971/1972 and 2011. Similarly, in Morocco, isolates were obtained from outbreaks in 1997 and 2004. The viruses isolated in 2004 showed evidence of 'evolutionary stasis', with haemagglutinin and non-structural protein 1 sequences most similar to those of viruses isolated decades earlier. In conclusion, effective surveillance of equids in the Maghreb region, where there is potential for virus re-emergence, should be encouraged.
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Affiliation(s)
- Hadda Kareche
- ESPA Laboratory, Department of Veterinary Sciences, Institute of Veterinary Sciences and Agronomic Sciences, University of Batna1-El-Hadj Lakhdar, 05000 Batna, Algeria.
| | - Janet M Daly
- One Virology, School of Veterinary Medicine and Science and Wolfson Centre for Global Virus Research, University of Nottingham, Sutton Bonington Campus, LE12 5RD, UK
| | - Farouk Laabassi
- ESPA Laboratory, Department of Veterinary Sciences, Institute of Veterinary Sciences and Agronomic Sciences, University of Batna1-El-Hadj Lakhdar, 05000 Batna, Algeria
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3
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Equine Influenza Virus and Vaccines. Viruses 2021; 13:v13081657. [PMID: 34452521 PMCID: PMC8402878 DOI: 10.3390/v13081657] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 07/27/2021] [Accepted: 07/28/2021] [Indexed: 01/01/2023] Open
Abstract
Equine influenza virus (EIV) is a constantly evolving viral pathogen that is responsible for yearly outbreaks of respiratory disease in horses termed equine influenza (EI). There is currently no evidence of circulation of the original H7N7 strain of EIV worldwide; however, the EIV H3N8 strain, which was first isolated in the early 1960s, remains a major threat to most of the world's horse populations. It can also infect dogs. The ability of EIV to constantly accumulate mutations in its antibody-binding sites enables it to evade host protective immunity, making it a successful viral pathogen. Clinical and virological protection against EIV is achieved by stimulation of strong cellular and humoral immunity in vaccinated horses. However, despite EI vaccine updates over the years, EIV remains relevant, because the protective effects of vaccines decay and permit subclinical infections that facilitate transmission into susceptible populations. In this review, we describe how the evolution of EIV drives repeated EI outbreaks even in horse populations with supposedly high vaccination coverage. Next, we discuss the approaches employed to develop efficacious EI vaccines for commercial use and the existing system for recommendations on updating vaccines based on available clinical and virological data to improve protective immunity in vaccinated horse populations. Understanding how EIV biology can be better harnessed to improve EI vaccines is central to controlling EI.
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Abstract
Serologic tests for equine influenza virus (EIV) antibodies are used for many purposes, including retrospective diagnosis, subtyping of virus isolates, antigenic comparison of different virus strains, and measurement of immune responses to EIV vaccines. The hemagglutination inhibition (HI) assay, single radial hemolysis (SRH), and serum micro-neutralization tests are the most widely used for these purposes and are described here. The presence of inhibitors of hemagglutination in equine serum complicates interpretation of HI assay results, and there are alternative protocols (receptor-destroying enzyme, periodate, trypsin-periodate) for their removal. With the EIV H3N8 strains in particular, equine antibody titers may be magnified by pre-treating the HI test antigen with Tween-80 and ether. The SRH assay offers stronger correlations between serum antibody titers and protection from disease. Other tests are sometimes used for specialized purposes such as the neuraminidase-inhibition assay for subtyping, or ELISA for measuring different specific antibody isotypes, and are not described here.
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Affiliation(s)
- Thomas M Chambers
- Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY, USA.
| | - Stephanie E Reedy
- Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY, USA
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5
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Abstract
Equine influenza virus (EIV) is a common respiratory pathogen of horses and other equids in most parts of the world. EIV are Type A influenza viruses and two subtypes are known: H3N8 and H7N7. Both are believed to have evolved from avian influenza virus ancestors. The H3N8 subtype circulates widely, but the H7N7 subtype is thought to be extinct. The clinical disease in horses, caused by either subtype, is an upper respiratory infection of varying severity depending upon the immune status of the individual animal. It is not normally life-threatening in itself except in very young foals; however it predisposes infected equids to secondary infections capable of producing life-threatening pneumonias. Vaccines are available and widely used in some horse populations, but their effectiveness is limited by antigenic drift and other factors, and vaccinated animals with subclinical infections have been responsible for introduction of EIV into susceptible populations. EIV has spread into canines.
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6
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Paungpin W, Wiriyarat W, Chaichoun K, Tiyanun E, Sangkachai N, Changsom D, Poltep K, Ratanakorn P, Puthavathana P. Serosurveillance for pandemic influenza A (H1N1) 2009 virus infection in domestic elephants, Thailand. PLoS One 2017; 12:e0186962. [PMID: 29073255 PMCID: PMC5658122 DOI: 10.1371/journal.pone.0186962] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 10/10/2017] [Indexed: 01/30/2023] Open
Abstract
The present study conducted serosurveillance for the presence of antibody to pandemic influenza A (H1N1) 2009 virus (H1N1pdm virus) in archival serum samples collected between 2009 and 2013 from 317 domestic elephants living in 19 provinces situated in various parts of Thailand. To obtain the most accurate data, hemagglutination-inhibition (HI) assay was employed as the screening test; and sera with HI antibody titers ≥20 were further confirmed by other methods, including cytopathic effect/hemagglutination based-microneutralization (microNT) and Western blot (WB) assays using H1N1pdm matrix 1 (M1) or hemagglutinin (HA) recombinant protein as the test antigen. Conclusively, the appropriate assays using HI in conjunction with WB assays for HA antibody revealed an overall seropositive rate of 8.5% (27 of 317). The prevalence of antibody to H1N1pdm virus was 2% (4/172) in 2009, 32% (17/53) in 2010, 9% (2/22) in 2011, 12% (1/8) in 2012, and 5% (3/62) in 2013. Notably, these positive serum samples were collected from elephants living in 7 tourist provinces of Thailand. The highest seropositive rate was obtained from elephants in Phuket, a popular tourist beach city. Young elephants had higher seropositive rate than older elephants. The source of H1N1pdm viral infection in these elephants was not explored, but most likely came from close contact with the infected mahouts or from the infected tourists who engaged in activities such as elephant riding and feeding. Nevertheless, it could not be excluded that elephant-to-elephant transmission did occur.
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Affiliation(s)
- Weena Paungpin
- Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
- The Monitoring and Surveillance Center for Zoonotic Diseases in Wildlife and Exotic Animals, Faculty of Veterinary Science, Mahidol University, Nakhon Pathom, Thailand
| | - Witthawat Wiriyarat
- The Monitoring and Surveillance Center for Zoonotic Diseases in Wildlife and Exotic Animals, Faculty of Veterinary Science, Mahidol University, Nakhon Pathom, Thailand
| | - Kridsada Chaichoun
- The Monitoring and Surveillance Center for Zoonotic Diseases in Wildlife and Exotic Animals, Faculty of Veterinary Science, Mahidol University, Nakhon Pathom, Thailand
| | - Ekasit Tiyanun
- One Health Animal Clinic, Mahidol University Nakhon Sawan Campus, Nakhon Sawan, Thailand
| | - Nareerat Sangkachai
- The Monitoring and Surveillance Center for Zoonotic Diseases in Wildlife and Exotic Animals, Faculty of Veterinary Science, Mahidol University, Nakhon Pathom, Thailand
| | - Don Changsom
- Center for Research and Innovation, Faculty of Medical Technology, Mahidol University, Nakhon Pathom, Thailand
| | - Kanaporn Poltep
- The Monitoring and Surveillance Center for Zoonotic Diseases in Wildlife and Exotic Animals, Faculty of Veterinary Science, Mahidol University, Nakhon Pathom, Thailand
| | - Parntep Ratanakorn
- The Monitoring and Surveillance Center for Zoonotic Diseases in Wildlife and Exotic Animals, Faculty of Veterinary Science, Mahidol University, Nakhon Pathom, Thailand
| | - Pilaipan Puthavathana
- Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
- Center for Research and Innovation, Faculty of Medical Technology, Mahidol University, Nakhon Pathom, Thailand
- Center for Emerging and Neglected Infectious Disease, Mahidol University, Nakhon Pathom, Thailand
- * E-mail:
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Kinsley R, Scott SD, Daly JM. Controlling equine influenza: Traditional to next generation serological assays. Vet Microbiol 2016; 187:15-20. [PMID: 27066704 DOI: 10.1016/j.vetmic.2016.03.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 02/29/2016] [Accepted: 03/08/2016] [Indexed: 01/20/2023]
Abstract
Serological assays provide an indirect route for the recognition of infectious agents via the detection of antibodies against the infectious agent of interest within serum. Serological assays for equine influenza A virus can be applied for different purposes: diagnosing infections; subtyping isolates; surveillance of circulating strains; and to evaluate the efficacy of vaccines before they reach the market. Haemagglutination inhibition (HI) and single radial haemolysis (SRH) assays are most commonly used in the equine field. This review outlines how both these assays together with virus neutralization (VN) and ELISA are performed, interpreted and applied for the control of equine influenza, giving the limitations and advantages of each. The pseudotyped virus neutralization assay (PVNA) is also discussed as a promising prospect for the future of equine influenza virus serology.
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Affiliation(s)
- Rebecca Kinsley
- Viral Pseudotype Unit, School of Pharmacy, University of Kent, Central Avenue, Chatham Maritime ME4 4TB, UK.
| | - Simon D Scott
- Viral Pseudotype Unit, School of Pharmacy, University of Kent, Central Avenue, Chatham Maritime ME4 4TB, UK.
| | - Janet M Daly
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington Campus, Leicestershire LE12 5RD, UK.
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Abstract
Equine influenza virus (EIV) is a common respiratory pathogen of horses and other equids in most parts of the world. EIV are Type A influenza viruses and two subtypes are known: H3N8 and H7N7. Both are believed to have evolved from avian influenza virus ancestors. The H3N8 subtype circulates widely, but the H7N7 subtype is thought to be extinct. The clinical disease in horses, caused by either subtype, is an upper respiratory infection of varying severity depending upon the immune status of the individual animal. It is not normally life-threatening in itself except in very young foals; however it predisposes infected equids to secondary infections capable of producing life-threatening pneumonias. Vaccines are available and widely used in some horse populations, but their effectiveness is limited by antigenic drift and other factors, and vaccinated animals with subclinical infections have been responsible for introduction of EIV into susceptible populations. EIV has spread into canines.
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Affiliation(s)
- Thomas M Chambers
- Department of Veterinary Science, OIE Reference Laboratory for Equine Influenza, Maxwell H. Gluck Equine Research Center, University of Kentucky, 1400 Nicholasville Road, Lexington, KY, 40546-0099, USA,
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9
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Abstract
Serologic tests for equine influenza virus (EIV) antibodies are used for many purposes, including retrospective diagnosis, subtyping of virus isolates, antigenic comparison of different virus strains, and measurement of immune responses to EIV vaccines. The hemagglutination-inhibition (HI), single radial hemolysis (SRH), and serum micro-neutralization tests are the most widely used for these purposes and are described here. The presence of inhibitors of hemagglutination in equine serum complicates interpretation of HI assay results, and there are alternative protocols (receptor-destroying enzyme, periodate, trypsin-periodate) for their removal. With the EIV H3N8 strains in particular, equine antibody titers may be magnified by pretreating the HI test antigen with Tween-80 and ether. The SRH assay offers stronger correlations between serum antibody titers and protection from disease. Other tests are sometimes used for specialized purposes such as the neuraminidase-inhibition assay for subtyping, or ELISA for measuring different specific antibody isotypes, and are not described here.
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Affiliation(s)
- Thomas M Chambers
- Department of Veterinary Science, OIE Reference Laboratory for Equine Influenza, Maxwell H. Gluck Equine Research Center, University of Kentucky, 1400 Nicholasville Road, Lexington, KY, 40546-0099, USA,
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Mather S, Scott S, Temperton N, Wright E, King B, Daly J. Current progress with serological assays for exotic emerging/re-emerging viruses. Future Virol 2013. [DOI: 10.2217/fvl.13.60] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Recent decades have witnessed an unprecedented rise in the outbreak occurrence of infectious and primarily zoonotic viruses. Contributing factors to this phenomenon include heightened global connectivity via air travel and international trade links, as well as man-made environmental alterations, such as deforestation and climate change, which all serve to bring humans into closer contact with animal reservoirs and alter the habitat of vectors, thus facilitating the transmission of viruses between species. Serological assays are integral to tracking the epidemiological spread of a virus and evaluating mass vaccination programs by quantifying neutralizing antibody responses raised against antigenic epitopes on the viral surface. However, conventional serological tests are somewhat marred by equipment and reagent costs, the necessity for high-containment laboratories for studying many emerging viruses, and interlaboratory variability, among other issues. This review details ‘next-generation’ assays aimed at addressing some of the persistent problems with viral serology, focusing on how manipulating the genomes of RNA viruses can produce attenuated or chimeric viruses that can be exploited as surrogate viruses in neutralization assays. Despite the undoubted promise of such novel serological platforms, it must be remembered that these assays have to withstand rigorous validation and standardization measures before they can play an integral role in curtailing the severity of future emerging virus outbreaks.
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Affiliation(s)
- Stuart Mather
- Viral Pseudotype Unit (Medway), School of Pharmacy, University of Kent, Chatham, Kent, ME4 4TB, UK
| | - Simon Scott
- Viral Pseudotype Unit (Medway), School of Pharmacy, University of Kent, Chatham, Kent, ME4 4TB, UK
| | - Nigel Temperton
- Viral Pseudotype Unit (Medway), School of Pharmacy, University of Kent, Chatham, Kent, ME4 4TB, UK
| | - Edward Wright
- Viral Pseudotype Unit (Fitzrovia), School of Life Sciences, University of Westminster, London, W1W 6UW, UK
| | - Barnabas King
- School of Veterinary Medicine & Science, University of Nottingham, Sutton Bonington Campus, Leicestershire, LE12 5RD, UK
| | - Janet Daly
- School of Veterinary Medicine & Science, University of Nottingham, Sutton Bonington Campus, Leicestershire, LE12 5RD, UK
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Abstract
Collective knowledge regarding the occurrence of influenza among swine is incomplete due to inconsistent surveillance of swine populations. In this chapter, we review what surveillance activities exist and some of the practical challenges encountered. Furthermore, to support robust surveillance activities, accurate laboratory assays are needed for the detection of the virus and viral nucleic acids within clinical samples, or for antiviral antibodies in serum samples. The most common influenza diagnostic assays used for swine are explained and their use as surveillance tools evaluated.
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12
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Improved high-throughput virus neutralisation assay for antibody estimation against pandemic and seasonal influenza strains from 2009 to 2011. J Virol Methods 2013; 189:341-7. [DOI: 10.1016/j.jviromet.2013.03.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Revised: 02/26/2013] [Accepted: 03/05/2013] [Indexed: 11/18/2022]
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Kim HR, Lee KK, Kwon YK, Kang MS, Moon OK, Park CK. Comparison of serum treatments to remove nonspecific inhibitors from chicken sera for the hemagglutination inhibition test with inactivated H5N1 and H9N2 avian Influenza A virus subtypes. J Vet Diagn Invest 2012; 24:954-8. [PMID: 22807505 DOI: 10.1177/1040638712452732] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The hemagglutination inhibition (HI) assay is the standard diagnostic test for detection of antibodies to avian influenza viruses. It is well known that chicken serum does not require additional serum pretreatment to remove nonspecific inhibitors (NSIs). However, NSIs were recognized in certain Korean local breeds. In the present study, various treatments were compared to remove such NSIs. Heat treatment, red blood cell adsorption, and kaolin treatment did not remove NSIs effectively, and treatment with periodate only partly eliminated the NSIs. Receptor destroying enzyme (RDE) treatment appeared to effectively remove NSIs from chicken sera, regardless of breeds. It is proposed that RDE treatment should be included in the HI tests for serological diagnosis of avian Influenza A virus.
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Affiliation(s)
- Hye-Ryoung Kim
- Animal, Plant and Fisheries Quarantine and Inspection Agency, 175 Anyangro Manangu Anyangsi, Gyeonggido 430-757, Republic of Korea
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Rajão DS, Alves F, Del Puerto HL, Braz GF, Oliveira FG, Ciacci-Zanella JR, Schaefer R, dos Reis JKP, Guedes RMC, Lobato ZIP, Leite RC. Serological evidence of swine influenza in Brazil. Influenza Other Respir Viruses 2012; 7:109-12. [PMID: 22487322 PMCID: PMC5780754 DOI: 10.1111/j.1750-2659.2012.00366.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
The aim of this work was to detect serum antibodies specific to influenza viruses in swine in Brazil. Serum samples of 355 pigs from 17 herds in Minas Gerais state were tested by hemagglutination inhibition (HI) for antibodies against H1N1 swine (SIV) and human influenza viruses, and H3N2 SIV. HI revealed that 158 animals (44·5%) and 11 herds (64·7%) were positive for H1N1 SIV, 36 animals (10·1%) and four herds (23·5%) were positive for H3N2 SIV, and 136 animals (38·3%) and 10 herds (58·8%) were positive for H1N1 human. This study indicates that swine influenza is disseminated throughout Minas Gerais state, Brazil.
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Affiliation(s)
- Daniela S Rajão
- Preventive Veterinary Medicine Department, Veterinary School, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil 31270-901.
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Immunogenicity and clinical protection against equine influenza by DNA vaccination of ponies. Vaccine 2012; 30:3965-74. [PMID: 22449425 DOI: 10.1016/j.vaccine.2012.03.026] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Revised: 02/09/2012] [Accepted: 03/12/2012] [Indexed: 11/24/2022]
Abstract
Equine influenza A (H3N8) virus infection is a leading cause of respiratory disease in horses, resulting in widespread morbidity and economic losses. As with influenza in other species, equine influenza strains continuously mutate, often requiring the development of new vaccines. Current inactivated (killed) vaccines, while efficacious, only offer limited protection against diverse subtypes and require frequent boosts. Research into new vaccine technologies, including gene-based vaccines, aims to increase the neutralization potency, breadth, and duration of protective immunity. Here, we demonstrate that a DNA vaccine expressing the hemagglutinin protein of equine H3N8 influenza virus generates homologous and heterologous immune responses, and protects against clinical disease and viral replication by homologous H3N8 virus in horses. Furthermore, we demonstrate that needle-free delivery is as efficient and effective as conventional parenteral injection using a needle and syringe. These findings suggest that DNA vaccines offer a safe, effective, and promising alternative approach for veterinary vaccines against equine influenza.
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