Design and characterization of a consensus hemagglutinin vaccine immunogen against H3 influenza A viruses of swine

Publication date: Available online 12 October 2019Source: Veterinary MicrobiologyAuthor(s): Haiyan Sun, Jung-Hyang Sur, Sarah Sillman, David Steffen, Hiep L.X. VuAbstractThe substantial genetic diversity exhibited by influenza A viruses of swine (IAV-S) represents the main challenge for the development of a broadly protective vaccine against this important pathogen. The consensus vaccine immunogen has proven an effective vaccinology approach to overcome the extraordinary genetic diversity of RNA viruses. In this project, we sought to determine if a consensus IAV-S hemagglutinin (HA) immunogen would elicit broad protective immunity in pigs. To address this question, a consensus HA gene (designated H3-CON.1) was generated from a set of 1,112 H3 sequences of IAV-S recorded in GenBank from 2011 to 2015. The consensus HA gene and a HA gene of a naturally occurring H3N2 IAV-S strain (designated H3-TX98) were expressed using the baculovirus expression system and emulsified in an oil-in-water adjuvant to be used for vaccination. Pigs vaccinated with H3-CON.1 immunogen elicited broader levels of cross-reactive neutralizing antibodies and interferon gamma secreting cells than those vaccinated with H3-TX98 immunogen. After challenge infection with a fully infectious H3N2 IAV-S isolate, the H3-CON.1-vaccinated pigs shed significantly lower levels of virus in their nasal secretions than the H3-TX98-vaccinated pigs. Collectively, the data provide a proof-of-evidence that the consensus immu...
Source: Veterinary Microbiology - Category: Veterinary Research Source Type: research

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Influenza A virus infection is a global health threat to livestock and humans, causing substantial mortality and morbidity. As both pigs and humans are readily infected with influenza viruses of similar subtype, the pig is a robust and appropriate model for investigating swine and human disease. We evaluated the efficacy of the human cold-adapted 2017–2018 quadrivalent seasonal LAIV in pigs against H1N1pdm09 challenge. LAIV immunized animals showed significantly reduced viral load in nasal swabs. There was limited replication of the H1N1 component of the vaccine in the nose, a limited response to H1N1 in the lung lym...
Source: Frontiers in Immunology - Category: Allergy & Immunology Source Type: research
This study reports virological and epidemiological data accumulated through passive surveillance conducted during 1,825 herd visits from 2011 to 2018. Among them, 887 (48.6%) tested swIAV-positive. The proportion of positive cases remained stable year-on-year and year-round. The European avian-like swine H1N1 (H1avN1) virus was the most frequently identified (69.6%), and was widespread across the country. The European human-like reassortant swine H1N2 (H1huN2) virus accounted for 22.1% and was only identified in the north-western quarter and recently in the far north. The 2009 pandemic H1N1 (H1N1pdm) virus (3.6%) was detec...
Source: Veterinary Microbiology - Category: Veterinary Research Source Type: research
Mark K. Slifka1* and Ian J. Amanna2 1Division of Neuroscience, Oregon National Primate Research Center, Oregon Health &Science University, Beaverton, OR, United States2Najít Technologies, Inc., Beaverton, OR, United States Vaccines play a vital role in protecting our communities against infectious disease. Unfortunately, some vaccines provide only partial protection or in some cases vaccine-mediated immunity may wane rapidly, resulting in either increased susceptibility to that disease or a requirement for more booster vaccinations in order to maintain immunity above a protective level. The durability of a...
Source: Frontiers in Immunology - Category: Allergy & Immunology Source Type: research
In conclusion, the reported results highlight the importance of AIV attachment to trachea in many avian species. Finally, the importance of chickens and mallards in AIVs dynamics was illustrated by the abundant AIV attachment observed. Introduction Influenza A viruses (IAVs) are pathogens of global concern in both human and veterinary medicine (Webster et al., 1992; Stöhr, 2002; Olsen et al., 2006; Wiethoelter et al., 2015). Wild birds are well-described hosts of avian influenza viruses (AIVs) and longitudinal surveillance studies have demonstrated a plethora of low pathogenic AIVs (LPAIVs) circulating in wild...
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research
In this study, we used a swine pH1N1 challenge virus to investigate the efficacy of whole inactivated virus vaccines homologous or heterologous to the challenge virus as well as a commercial vaccine. We found that vaccine-mediated protection was most effective when vaccine antigen and challenge virus were homologous and correlated with the specific production of neutralising antibodies and a cellular response to the challenge virus. We conclude that a conventional whole inactivated SwIV vaccine must be antigenically matched to the challenge strain to be an effective control measure. PMID: 30914224 [PubMed - as supplied by publisher]
Source: Vaccine - Category: Allergy & Immunology Authors: Tags: Vaccine Source Type: research
Publication date: Available online 12 March 2019Source: Veterinary MicrobiologyAuthor(s): Svenja Mamerow, Robert Scheffter, Susanne Röhrs, Olga Stech, Ulrike Blohm, Theresa Schwaiger, Charlotte Schröder, Reiner Ulrich, Jan Schinköthe, Martin Beer, Thomas C. Mettenleiter, Jürgen StechAbstractInfluenza A viruses (IAV) have caused seasonal epidemics and severe pandemics in humans. Novel pandemic strains as in 2009 may emerge from pigs, serving as perpetual virus reservoir. However, reliably effective vaccination has remained a key issue for humans and swine. Here, we generated a novel double-attenuated inf...
Source: Veterinary Microbiology - Category: Veterinary Research Source Type: research
We describe here that pre-exposure with a live virus generated via a A/WSN/1933(H1N1) reverse genetics system resulted in a significant reduction of viral shedding from pigs exposed to either a swine H1N1 virus or a swine H3N2 virus. At 3-day post challenge (DPC), approximately 1 log and 1.5 logs reductions of viral shedding were observed in the swine H1N1- and H3N2-challenged vaccinated pigs when compared to unvaccinated animals. A further decline in viral load was observed at 5 DPC where viral shedding was decreased by greater than 3 logs in vaccinated pigs receiving either the H1N1 or H3N2 virus challenge. Although the ...
Source: Veterinary Microbiology - Category: Veterinary Research Source Type: research
This study investigated the prevalence of IAV in commercial swine herds. A total of 1,878 oral fluid samples were collected from pigs of all ages from 201 commercial farms located in North Carolina and South Carolina. Sixty-eight oral fluid samples from 35 farms were positive by MP gene PCR with an overall IAV-positivity of 3.6%. On the herd level, the percentage of IAV positivity was 17.4%. Fifty-six viruses were subtyped, while 12 were partly subtyped or not subtyped at all. Using de novo assembly, complete sequences were obtained for 59 HA genes. The majority of IAVs subtyped had an H1 HA demonstrating a considerable pr...
Source: Veterinary Microbiology - Category: Veterinary Research Source Type: research
AbstractSwine influenza viruses (swIAVs) are known to persist endemically in farrow-to-finish pig farms, leading to repeated swine flu outbreaks in successive batches of pigs at a similar age (mostly around 8  weeks of age). This persistence in European swine herds involves swIAVs from European lineages including H1avN1, H1huN2, H3N2, the 2009 H1N1 pandemic virus and their reassortants. The specific population dynamics of farrow-to-finish pig farms, the immune status of the animals at infection-time, the co-circulation of distinct subtypes leading to consecutive or concomitant infections have been evidenced as factors...
Source: Veterinary Research - Category: Veterinary Research Source Type: research
Conclusion Further testing in larger trials needs to be done to be sure these initial results hold true and that the vaccine patch is safe and effective. This is the first time these flu microneedle patches have been tested on humans, and the study was relatively small, with only 100 participants. But if the results are confirmed, this new method of delivering the flu vaccination could make a big difference. The patches could have several main advantages over traditional injections: they may be preferred by people who dislike needles and avoid vaccination because of the fear of pain it may be quicker and easier to admi...
Source: NHS News Feed - Category: Consumer Health News Tags: Medical practice Medication Swine flu Source Type: news
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