A cross-sectional study on the understanding and attitudes toward influenza and influenza vaccines among different occupational groups in China

This study aimed to assess the level of knowledge regarding influenza viruses and vaccines among different professional groups to investigate the reasons for vaccine hesitancy. We collected 2190 questionnaires regarding influenza vaccines in China in 2022. The respondents were categorized into the general population (GP), foreign affairs workforce population (FAWP), and veterinary workforce population (VWP) according to their job positions. Linear regression was used to assess the association between multiple factors and influenza vaccination rates. The association between work and influenza vaccination rates was also assessed by grouping different workforce populations. The vaccination rate of the GP was higher than that of the VWP (odds ratio: 1.342, 95% confidence interval: 1.025-1.853), surpassing the rates reported in previous studies. This may be attributed to heightened concerns about infectious diseases influenced by the ongoing coronavirus disease 2019 pandemic. Despite the VWP's more in-depth knowledge of the VWP on zoonotic diseases and their recognition of their importance, there was no significant difference in influenza knowledge among the three populations. This discrepancy contrasts with the observed differences in vaccination rates. Further investigation revealed that, compared with FAWP, the price of vaccines emerged as a primary influencing factor for vaccination rates (odds ratio:0.398, 95%CI; 0.280-0.564). General concerns regarding the protective effects and side effects of vaccines were also noted.

The attenuated African swine fever vaccine HLJ/18-7GD provides protection against emerging prevalent genotype II variants in China

Genetic changes have occurred in the genomes of prevalent African swine fever viruses (ASFVs) in the field in China, which may change their antigenic properties and result in immune escape. There is usually poor cross-protection between heterogonous isolates, and, therefore, it is important to test the cross-protection of the live attenuated ASFV vaccines against current prevalent heterogonous isolates. In this study, we evaluated the protective efficacy of the ASFV vaccine candidate HLJ/18-7GD against emerging isolates. HLJ/18-7GD provided protection against a highly virulent variant and a lower lethal isolate, both derived from genotype II Georgia07-like ASFV and isolated in 2020. HLJ/18-7GD vaccination prevented pigs from developing ASF-specific clinical signs and death, decreased viral shedding via the oral and rectal routes, and suppressed viral replication after challenges. However, HLJ/18-7GD vaccination did not provide solid cross-protection against genotype I NH/P68-like ASFV challenge in pigs. HLJ/18-7GD vaccination thus shows great promise as an alternative strategy for preventing and controlling genotype II ASFVs, but vaccines providing cross-protection against different ASFV genotypes may be needed in China.

Transcriptome profiles of organ tissues from pigs experimentally infected with African swine fever virus in early phase of infection

African swine fever, caused by African swine fever virus (ASFV), is a highly contagious and fatal disease that poses a significant threat to the global pig industry. The limited information on ASFV pathogenesis and ASFV-host interactions has recently prompted numerous transcriptomic studies. However, most of these studies have focused on elucidating the transcriptome profiles of ASFV-infected porcine alveolar macrophages in vitro. Here, we analyzed dynamic transcriptional patterns in vivo in nine organ tissues (spleen, submandibular lymph node, mesenteric lymph node, inguinal lymph node, tonsils, lungs, liver, kidneys, and heart) obtained from pigs in the early stages of ASFV infection (1 and 3 d after viremia). We observed rapid spread of ASFV to the spleen after viremia, followed by broad transmission to the liver and lungs and subsequently, the submandibular and inguinal lymph nodes. Profound variations in gene expression patterns were observed across all organs and at all time-points, providing an understanding of the distinct defence strategies employed by each organ against ASFV infection. All ASFV-infected organs exhibited a collaborative response, activating immune-associated genes such as S100A8, thereby triggering a pro-inflammatory cytokine storm and interferon activation. Functional analysis suggested that ASFV exploits the PI3K-Akt signalling pathway to evade the host immune system. Overall, our findings provide leads into the mechanisms underlying pathogenesis and host immune responses in different organs during the early stages of infection, which can guide further explorations, aid the development of efficacious antiviral strategies against ASFV, and identify valuable candidate gene targets for vaccine development.

Progress and persistence of diseases of high consequence to livestock in the United States

The USDA/ARS-National Disease Center (NADC) will celebrate its 65th anniversary of existence in November 2026. NADC continues as one of the world's premier animal health research centers conducting basic and applied research on endemic diseases with economic impact on U.S. livestock and wildlife. This research center also supports a program studying important food safety pathogens such as Salmonella, E. coli and Campylobacter. NADC has contributed significantly to the elimination of a few diseases, notably hog cholera and milk fever, and made progress in reducing the impact of many other animal diseases through vaccines, therapies and managerial recommendations. Despite nearly 65 years of targeted research on these diseases and much progress, some of these continue to persist. The reasons for such persistence varies for each disease condition and they are often multifactorial involving host susceptibility, virulence and even environmental conditions. Individually and in aggregate, these disease conditions have a massive economic impact and can be devasting to animal producers, owners and individuals that become infected through zoonotic disease agents such as tuberculosis, leptospirosis and avian influenza. They also diminish the health, well-being and welfare of affected animals, which directly affects the food supply. The NADC is using all available technologies including genomic, biochemical, reverse genetics, and vaccine trials in the target host to combat these significant diseases. We review the progress and reasons for persistence of selected diseases and food safety pathogens as well as the progress and potential outcomes should research and programmatic plans to eliminate these disease conditions cease.

Transboundary viral diseases of pigs, poultry and ruminants in Southeast Asia: a systematic review

Livestock is a strategic part of the small-farm economy in Southeast Asia's society, providing food income, clothing, fertilizer, and draught power. However, incidences or outbreaks of transboundary animal diseases (TADs) are due to converging factors such as the natural hazards' aftermath, climate change, deforestation, urban growth, changing production conditions, and market chains. Therefore, this affects productivity and impacts farmers' livelihoods with small holdings. The literature review was carried out to understand the current situation of TADs in Southeast Asia, identifying knowledge gaps to provide actions for disease control and prevention in the region. We have attempted to summarise the scientific literature in English on the prevalence data of TADs in Southeast Asia between 2011 and March 2022. Relatively few studies evaluated the distribution of TAD, where most of the studies focused on diseases that are important for international trade, such as avian influenza (AI), African swine fever (ASF), classical swine fever (CSF), foot-and-mouth disease (FMD) and Newcastle disease (ND). Traditional production systems have received little attention in such studies as they belonged to mainly smallholders. The outbreaks of ASF and lumpy skin disease (LSD) in 2019 resulted in increased research activity between 2019-2022, while the other TADs were ignored in this period. For new emerging TADs diseases such as ASF and LSD, there is only information about the first detection without prevalence information. Therefore, further epidemiological investigations are necessary to reduce the gaps in disease surveillance reporting systems and support the prevention and reduction of further outbreaks.

Genomic diversity and evolutionary dynamics of Influenza A viruses in Colombian swine: implications for one health surveillance and control

Influenza A viruses (IAV) impose significant respiratory disease burdens in both swine and humans worldwide, with frequent human-to-swine transmission driving viral evolution in pigs and highlighting the risk at the animal-human interface. Therefore, a comprehensive One Health approach (interconnection among human, animal, and environmental health) is needed for IAV prevention, control, and response. Animal influenza genomic surveillance remains limited in many Latin American countries, including Colombia. To address this gap, we genetically characterized 170 swine specimens from Colombia (2011-2017). Whole genome sequencing revealed a predominance of pandemic-like H1N1 lineage, with a minority belonging to H3N2 and H1N2 human seasonal-like lineage and H1N1 early classical swine lineages. Significantly, we have identified reassortant and recombinant viruses (H3N2, H1N1) not previously reported in Colombia. This suggests a broad genotypic viral diversity, likely resulting from reassortment between classical endemic viruses and new introductions established in Colombia's swine population (e.g. the 2009 H1N1 pandemic). Our study highlights the importance of a One Health approach in disease control, particularly in an ecosystem where humans are a main source of IAV to swine populations, and emphasizes the need for continued surveillance and enhanced biosecurity measures. The co-circulation of multiple subtypes in regions with high swine density facilitates viral exchange, underscoring the importance of monitoring viral evolution to inform vaccine selection and public health policies locally and globally.

Spatial patterns of influenza A virus spread across compartments in commercial swine farms in the United States

Multiple genetic variants of H1 and H3 influenza A viruses (IAVs) circulate concurrently in US swine farms. Understanding the spatial transmission patterns of IAVs among these farms is crucial for developing effective control strategies and mitigating the emergence of novel IAVs. In this study, we analysed 1909 IAV genomic sequences from 785 US swine farms, representing 33 farming systems across 12 states, primarily in the Midwest from 2004 to 2023. Bayesian phylogeographic analyses were performed to identify the dispersal patterns of both H1 and H3 virus genetic lineages and to elucidate their spatial migration patterns within and between different systems. Our results showed that both intra-system and inter-system migrations occurred between the swine farms, with intra-system migrations being more frequent. However, migration rates for H1 and H3 IAVs were similar between intra-system and inter-system migration events. Spatial migration patterns aligned with expected pig movement across different compartments of swine farming systems. Sow-Farms were identified as key sources of viruses, with bi-directional migration observed between these farms and other parts of the system, including Wean-to-Finish and Gilt-Development-Units. High intra-system migration was detected across farms in the same region, while spread to geographically distant intra- and inter-system farms was less frequent. These findings suggest that prioritizing resources towards systems frequently confronting influenza problems and targeting pivotal source farms, such as sow farms, could be an effective strategy for controlling influenza in US commercial swine operations.

Clustering broiler farmers based on their behavioural differences towards biosecurity to prevent highly pathogenic avian influenza

Highly pathogenic avian influenza (HPAI) is an important zoonotic disease. The study aims to identify farmer behaviour types to inform the design of behaviour change programmes for mitigating the transmission of HPAI. Therefore, the study utilised multivariate statistical analysis for gaining a better understanding of the relationships among farmers' 30 biosecurity behaviours, the risk of HPAI infection, and distinct features of commercial broiler farmers, which is different from using simple and few binary biosecurity measures. Convenience sampling was used to collect data from 303 Taiwan's farmers among which 40 farmers (13.2%) self-reported having had a HPAI outbreak in the study year while 16 farmers (5.3%) self-reported having had a HPAI outbreak in the past two years. Using categorical principal components analysis and a two-stage cluster analysis, four farmer clusters were identified with distinct features: 1)'Reserved' (4.6%) tended to choose 'No idea' for answering specific questions about HPAI; 2)'Secure' (76.3%) had a higher biosecurity status than the other farms; 3) 'Jeopardised' (16.8%) had a lower biosecurity status than the other farms; 4) 'No-response' (2.3%) tended to skip specific questions about HPAI. The biosecurity status of the 'Reserved' and 'No-response' clusters was undetermined, placing these farms at risk of HPAI infection. Compared to the 'Secure' cluster, the 'Jeopardised' cluster exhibited higher odds of self-reported HPAI in the study year (OR: 2.61, 95% CI: 1.22-5.58) and in the past two years (OR: 4.28, 95% CI: 1.39-13.19). Additionally, the 'Jeopardised' cluster showed increased odds of HPAI recurrence (OR: 4.01, 95% CI: 1.41-11.43). Our study demonstrates that inadequate biosecurity practices can elevate the occurrence or recurrence of HPAI outbreaks. The findings underscore the importance of distinguishing between these clusters to accurately assess the risk of HPAI infection across farms. Furthermore, understanding farmers' behaviours can inform the development of strategies aimed at behaviour change among farmers.

Development of a pig wean-quality score using machine-learning algorithms to characterize and classify groups with high mortality risk under field conditions

Mortality during the post-weaning phase is a critical indicator of swine production system performance, influenced by a complex interaction of multiple factors of the epidemiological triad. This study leveraged retrospective data from 1723 groups of pigs marketed within a US swine production system to develop a Wean-Quality Score (WQS) using machine learning techniques. The study evaluated three machine learning models, Random Forest, Support Vector Machine, and Gradient Boosting Machine, to classify groups having high or low 60-day mortality, where high mortality groups represented 25 % of the groups among the study population with the highest mortality values (n=431; 60-day mortality=9.98 %), and the remaining 75 % of the groups were of low mortality (n=1292; 60-day mortality=2.75 %). The best-performing model, Random Forest (RF), outperformed the other ML models in terms of accuracy (0.90), sensitivity (0.84), and specificity (0.92) metrics, and was then selected for further analysis, which consisted of creating the WQS and ranking the most important factors for classifying groups as high or low mortality. The most important factors ranked through the RF model to classify groups with high mortality were pre-weaning mortality, weaning age, average parity of litters in sow farms, and PRRS status. Additionally, stocking conditions such as stocking density and time to fill the barn were important predictors of high mortality. The WQS was developed and correlated (r = 0.74) with the actual 60-day mortality of the groups, offering a valuable tool for assessing post-weaning survivability in swine production systems before weaning. This study highlights the potential of machine learning and comprehensive data utilization to improve the assessment and management of weaned pig quality in commercial swine production, which producers can utilize to identify and intervene in groups, according to the WQS.

Investigation into the supplementation of a ferric sillen core-linked polymer on the health and physiological performance of broiler chickens

Poultry is a ubiquitous and highly sought-after protein source valued for its accessibility, notable protein content, and lack of religious constraints. However, the demand for poultry has resulted in a surge in intensive production practices. The transition from subsistence agricultural practices to intensive food production resulted in the widespread adoption of antibiotics for both therapeutic and economic purposes. These interventions were intended to enhance meat yield, promote bird health, and enhance cost-effectiveness of production. However, this inadvertently contributed to the rise of antimicrobial resistance (AMR). Therefore, the need to explore alternative approaches to mitigate the problems associated with AMR has become increasingly pressing. In response, metal-based compounds have emerged as a promising substitute to conventional antibiotics. In this study, the effects of a water soluble metallo-antimicrobial supplement, ferric sillen core-linked polymer (FSCLP), on body weight gain, feed conversion, water intake, volatile fatty acid (VFA) production, cecal microbiome and intestinal morphology in broilers was examined. The findings of this study suggested that the addition of the FSCLP resulted in better bird performance, even during a period of heat stress. Volatile fatty acids analysis of cecal contents indicated that there were significantly higher levels (p < 0.05) of butyric and valeric acids. Cecal microbiome analysis confirmed significantly lower abundance (p < 0.05) of Proteobacteria (e.g., E. coli) and a significantly greater abundance of VFA-producing bacteria such as Intestinimonas butyriciproducens, Blautia and Lachnospiraceae. The intestinal morphology data showed supplementation with the FSCLP at 80 ppm resulted in a significantly higher (p < 0.05) villus height of the jejunum. This study emphasises the potential of FSCLP as a feasible solution to the issues faced by AMR in chicken production, providing insights into its beneficial impacts on performance, microbial composition, and intestinal health.

Using Selenium-enriched Mutated Probiotics as Enhancer for Fertility Parameters in Mice

Increasing fertility rates have become one of the factors that concern all people in the world. Therefore, the study aims to use two mutated strains of probiotics enriched with selenium (PSe40/60/1 and BSe50/20/1) to improve fertility. Thirty Swiss albino male mice were divided into three groups; control, LP + S was given Lactobacillus plantarum PSe40/60/1 plus selenium, and BL + S was given Bifidobacterium longum BSe50/20/1 plus selenium. Free testosterone, LH, and FSH were measured in serum by biochemical analysis. Testicular tissues were examined by histopathological analysis. The count and motility of sperm, and sperm abnormalities were determined by microscopic examination. The method of qRT-PCR was used to detect gene expression of Tspyl1, Hsd3b6, and Star genes. The biochemical results showed that serum content of free testosterone (FT) hormone had significantly increase in the BL + S and LP + S groups compared with control. Levels of LH and FSH hormones were the highest in the BL + S group. The treated groups showed all developmental stages of spermatogenesis, including spermatogenesis, spermatocytes, and seminiferous tubule spermatids, as well as intact Sertoli cells and Leydig cells without changes. When compared to the control group, sperm count and motility increased in the BL + S group, while sperm abnormalities decreased. The expression of Tspyl1 gene in testicular tissues decreased in the LP + S and BL + S groups, while the expression of Star and Hsd3b6 genes was higher in the BL + S group and lower in the LP + S group compared with the control group. Therefore, Bifidobacterium longum BSe50/20/1 enriched with selenium could be useful in enhancing male fertility.

Risk factors associated with piglet pre-weaning mortality in a Midwestern U.S. swine production system from 2020 to 2022

Piglet pre-weaning mortality (PWM) is a significant issue in the U.S. swine industry, causing economic losses and raising sustainability and animal welfare concerns. This study conducted a multivariable analysis to identify factors associated with PWM in a Midwestern U.S. swine production system. Weekly data from 47 sow farms (7207 weaning weeks) were captured from January 2020 to December 2022. Initially, 29 variables regarding farm infrastructure, productivity parameters, health status, and interventions were selected for univariate analysis to assess their association with PWM. The initial multivariable analysis included the variables with P < 0.20 in the univariate analyses. A backward stepwise model selection was conducted by excluding variables with P > 0.05, and the final multivariable model consisted of 19 significant risk factors and 6 interaction terms. The overall average PWM for the study population was 14.02 %. Yearly variations in PWM were observed, with the highest recorded in 2020 (16.61 %) and the lowest in 2021 (15.78 %). Cohorts with a pond water source, lower farrowing rate (71.9 %), higher farrowing parity (5.1), shorter gestation length (116.2 days), and using oxytocin during farrowing had increased PWM. The higher productivity parameters such as mummies rate, stillborn rate, and average total born, the higher the PWM was. Additionally, health status and intervention-related factors were associated with PWM, where higher PWM rates were observed in herds facing porcine reproductive and respiratory syndrome virus (PRRSV) outbreaks, porcine epidemic diarrhea virus (PEDV) positive, the weeks before and during feed medication, and weeks without using Rotavirus vaccine or Rotavirus feedback. Altogether, these results corroborate that PWM is a multifactorial problem, and a better understanding of the risk factors is essential in developing strategies to improve survival rates. Therefore, this study identified the major risk factors associated with PWM for groups of pigs raised under field conditions, and the results underscore the significance of data analysis in comprehending the unique challenges and opportunities inherent to each system.

Dietary Dihydromyricetin Zinc Chelate Supplementation Improves the Intestinal Health of Magang Geese

To fulfill the nutritional requirements of poultry, effective Zn supplementation is required due to Zn deficiency in basic feed. In this study, we investigated the effects of DMY-Zn (dihydromyricetin zinc chelate) on the growth performance, morphology, and biochemical indices; the expression of intestinal barrier-related genes; the intestinal microflora; and the cecum metabolome of Magang geese. A total of 300 14-day-old Magang geese (equal number of males and females) with an average body weight of 0.82 ± 0.08 kg were randomly divided into five groups and fed a basal diet; these groups were given DMY-Zn (low, medium, or high level of DMY-Zn with 30, 55, or 80 mg/kg Zn added to the basal diet) or ZnSO4 (80 mg/kg Zn added) for 4 weeks. Our results revealed that DMY-Zn significantly impacts growth and biochemical indices and plays a significant role in regulating the intestinal barrier and microflora. DMY-Zn is involved in the upregulation of intestinal barrier gene (ZO1 and MUC2) expression, as well as upregulated Zn-related gene expression (ZIP5). On the other hand, a low concentration of DMY-Zn increased the ɑ diversity index and the abundance of Lactobacillus and Faecalibacterium. Additionally, a cecal metabolomics study showed that the main metabolic pathways affected by DMY-Zn were the pentose phosphate pathway, the biosynthesis of different alkaloids, and the metabolism of sphingolipids. In conclusion, DMY-Zn can reduce feed intake, increase the expression of intestinal barrier-related genes, help maintain the intestinal microflora balance, and increase the abundance of beneficial bacteria in the intestine to improve intestinal immunity.

Deficiency of hasB accelerated the clearance of Streptococcus equi subsp. Zooepidemicus through gasdermin d-dependent neutrophil extracellular traps

Streptococcus equi subsp. zooepidemicus (S. zooepidemicus, SEZ) is an essential zoonotic bacterial pathogen that can cause various inflammation, such as meningitis, endocarditis, and pneumonia. UDP-glucose dehydrogenase (hasB) is indispensable in synthesizing SEZ virulence factor hyaluronan capsules. Our study investigated the infection of hasB on mice response to SEZ by employing a constructed capsule-deficient mutant strain designated as the ΔhasB strain. This deficiency was associated with a reduced SEZ bacterial load in the mice's blood and peritoneal lavage fluid (PLF) post-infection. Besides, the ΔhasB SEZ strain exhibited a higher propensity for neutrophil infiltration and release of cell-free DNA (cfDNA) in vivo compared to the wild-type (WT) SEZ strain. In vitro experiments further revealed that ΔhasB SEZ more effectively induced the formation of neutrophil extracellular traps (NETs) containing histone 3 (H3), neutrophil elastase (NE), and DNA, than its WT counterpart. Moreover, the release of NETs was determined to be gasdermin D (GSDMD)-dependent during the infection process. Taken together, these findings underscore that the deficiency of the hasB gene in SEZ leads to enhanced GSDMD-dependent NET release from neutrophils, thereby reducing SEZ's capacity to resist NETs-mediated eradication during infection. Our finding paves the way for the development of innovative therapeutic strategies against SEZ.

Shedding reduction and immunity modulation in piglets with an inactivated Mycoplasma hyopneumoniae vaccine encapsulated in nanostructured SBA-15 silica

Mycoplasma (M.) hyopneumoniae is a primary etiological agent of porcine enzootic pneumonia (PEP), a disease that causes significant economic losses to pig farming worldwide. Current commercial M. hyopneumoniae vaccines induce partial protection, decline in preventing transmission of this pathogen or inducing complete immunity, evidencing the need for improving vaccines against PEP. In our study, we aimed to test the effectiveness of the SBA-15 ordered mesoporous silica nanostructured particles as an immune adjuvant of a vaccine composed of M. hyopneumoniae strain 232 proteins encapsulated in SBA-15 and administered by intramuscular route in piglets to evaluate the immune responses and immune-protection against challenge. Forty-eight 24-day-old M. hyopneumoniae-free piglets were divided into four experimental groups with different protocols, encompassing a commercial vaccine against M. hyopneumoniae, SBA-15 vaccine, SBA-15 adjuvant without antigens and a non-immunized group. All piglets were challenged with the virulent strain 232 of M. hyopneumoniae. Piglets that received the SBA-15 and commercial vaccine presented marked immune responses characterized by anti-M. hyopneumoniae IgA and IgG antibodies in serum, anti-M. hyopneumoniae IgA antibodies in nasal mucosa and showed an upregulation of IL-17 and IL-4 cytokines and downregulation of IFN-γ in lungs 35 days post-infection. Piglets immunized with SBA-15 vaccine presented a reduction of bacterial shedding compared to piglets immunized with a commercial bacterin. In addition, piglets from SBA-15 adjuvant suspension group presented increased IL-17 gene expression in the lungs without involvement of Th1 and Th2 responses after challenge. These results indicated that SBA-15 vaccine induced both humoral and cell-mediated responses in the upper respiratory tract and lungs, first site of replication and provided protection against M. hyopneumoniae infection with a homologous strain with reduction of lung lesions and bacterial shedding. Finally, these results enhance the potential use of new technologies such as nanostructured particles applied in vaccines for the pig farming industry.

Vaccination with a Lawsonia intracellularis subunit water in oil emulsion vaccine mitigated some disease parameters but failed to affect shedding

Lawsonia intracellularis is the causative agent of ileitis in swine that manifests as slower weight gain, mild or hemorrhagic diarrhea and/or death in severe cases. As an economically important swine pathogen, development of effective vaccines is important to the swine industry. In developing a subunit vaccine with three recombinant antigens - FliC, GroEL and YopN - we wanted to identify a formulation that would produce robust immune responses that reduce disease parameters associated with Lawsonia intracellularis infection. We formulated these three antigens with four adjuvants: Montanide ISA 660 VG, Montanide Gel 02 PR, Montanide IMS 1313 VG NST, and Montanide ISA 61 VG in an immunogenicity study. Groups vaccinated with formulations including Montanide ISA 660 VG or Montanide ISA 61 VG had significantly more robust immune responses than groups vaccinated with formulations including Montanide Gel 02 PR or Montanide IMS 1313 VG NST. In the challenge study, animals vaccinated with these antigens and Montanide ISA 61 VG had reduced lesion scores, reduced lesion lengths, and increased average daily gain, but no reduction in shedding relative to the control animals. This work shows that this vaccine formulation should be considered for future study in a field and performance trial.

Development of a fully automated chemiluminescent immunoassay for the quantitative and qualitative detection of antibodies against African swine fever virus p72

African swine fever (ASF), caused by ASF virus (ASFV), is a highly infectious and severe hemorrhagic disease of pigs that causes major economic losses. Currently, no commercial vaccine is available and prevention and control of ASF relies mainly on early diagnosis. Here, a novel automated double antigen sandwich chemiluminescent immunoassay (DAgS-aCLIA) was developed to detect antibodies against ASFV p72 (p72-Ab). For this purpose, recombinant p72 trimer was produced, coupled to magnetic particles as carriers and labeled with acridinium ester as a signal trace. Finally, p72-Ab can be sensitively and rapidly measured on an automated chemiluminescent instrument. For quantitative analysis, a calibration curve was established with a laudable linearity range of 0.21 to 212.0 ng/mL (R2 = 0.9910) and a lower detection limit of 0.15 ng/mL. For qualitative analysis, a cut-off value was set at 1.50 ng/mL with a diagnostic sensitivity of 100.00% and specificity of 98.33%. Furthermore, antibody response to an ASF gene-deleted vaccine candidate can be accurately quantified using this DAgS-aCLIA, as evidenced by early seroconversion as early as 7 days post-immunization and high antibody levels. Compared with available enzyme-linked immunosorbent assays, this DAgS-aCLIA demonstrated a wider linearity range of 4 to 16-fold, and excellent analytical sensitivity and agreement of over 95.60%. In conclusion, our proposed DAgS-aCLIA would be an effective tool to support ASF epidemiological surveillance.IMPORTANCEAfrican swine fever virus (ASFV) is highly contagious in wild boar and domestic pigs. There is currently no vaccine available for ASF, so serological testing is an important diagnostic tool. Traditional enzyme-linked immunosorbent assays provide only qualitative results and are time and resource consuming. This study will develop an automated chemiluminescent immunoassay (CLIA) that can quantitatively and qualitatively detect antibodies to ASFV p72, greatly reducing detection time and labour-intensive operation, and improving detection sensitivity and linearity range. This novel CLIA would serve as a reliable and convenient tool for ASF pandemic surveillance and vaccine development.

Intranasal delivery of a recombinant adenovirus vaccine encoding the PEDV COE elicits potent mucosal and systemic antibody responses in mice

Porcine epidemic diarrhea virus (PEDV) is an enteropathogenic coronavirus that causes substantial economic loss to the global pig industry. The emergence of PEDV variants has increased the need for new vaccines, as commercial vaccines confer inferior protection against currently circulating strains. It is well established that the induction of mucosal immunity is crucial for PEDV vaccines to provide better protection against PEDV infection. In this study, we constructed a recombinant adenovirus expressing the core neutralization epitope (COE) of G2b PEDV based on human adenovirus serotype 5 (Ad5). We evaluated the effects of different administration routes and doses of vaccine immunogenicity in Balb/c mice. Both intramuscular (IM) and intranasal (IN) administration elicited significant humoral responses, including COE-specific IgG in serum and mucosal secretions, along with serum-neutralizing antibodies. Moreover, IN delivery was more potent than IM in stimulating IgA in serum and mucosal samples and in dampening the immune response to the Ad5 vector. The immune response was stronger after high versus low dose IM injection, whereas no significant difference was observed between high and low IN doses. In summary, our findings provide important insights for developing novel PEDV vaccines.IMPORTANCEPorcine epidemic diarrhea (PED) is a highly contagious disease that has severe economic implications for the pork industry. Developing an effective vaccine against PEDV remains a necessity. Here, we generated a recombinant adenovirus vaccine based on Ad5 to express the COE protein of PEDV (rAd5-PEDV-COE) and systematically evaluated the immunogenicity of the adenovirus-vectored vaccine using different administration routes (intramuscular and intranasal) and doses in a mouse model. Our results show that rAd5-PEDV-COE induced potent systemic humoral response regardless of the dose or immunization route. Notably, intranasal delivery was superior to induce peripheral and mucosal IgA antibodies compared with intramuscular injection. Our data provide valuable insights into designing novel PEDV vaccines.

Duckweeds as edible vaccines in the animal farming industry

Animal diseases are among the most debilitating issues in the animal farming industry, resulting in decreased productivity and product quality worldwide. An emerging alternative to conventional injectable vaccines is edible vaccines, which promise increased delivery efficiency while maintaining vaccine effectiveness. One of the most promising platforms for edible vaccines is duckweeds, due to their high growth rate, ease of transformation, and excellent nutritional content. This review explores the potential, feasibility, and advantages of using duckweeds as platforms for edible vaccines. Duckweeds have proven to be superb feed sources, as evidenced by numerous improvements in both quantity (e.g., weight gain) and quality (e.g., yolk pigmentation). In terms of heterologous protein production, duckweeds, being plants, are capable of expressing proteins with complex structures and post-translational modifications. Research efforts have focused on the development of duckweed-based edible vaccines, including those against avian influenza, tuberculosis, Newcastle disease, and mastitis, among others. As with any emerging technology, the development of duckweeds as a platform for edible vaccines is still in its early stages compared to well-established injectable vaccines. It is evident that more proof-of-concept studies are required to bring edible vaccines closer to the current standards of conventional vaccines. Specifically, the duckweed expression system needs further development in areas such as yield and growth rate, especially when compared to bacterial and mammalian expression systems. Continued efforts in this field could lead to breakthroughs that significantly improve the resilience of the animal farming industry against disease threats.

The role of alginate oligosaccharide on boar semen quality: A research review

Alginate is the general term of a polysaccharide which is widely used in the area of pharmaceutics and the food industry and is known for its unique biological activities. However, due to the low water solubility and large viscosity of alginate, its development and utilization in the agricultural field are limited. Alginate oligosaccharide (AOS) is a degradable product derived from alginate and has attracted much attention in recent years because of its specific characteristics such as a low molecular weight, high water solubility, and non-toxicity. Boar semen quality, which is affected by various factors, is an important indicator for measuring reproductive performance of boars. With the development of artificial insemination technology, high quality semen has been more and more important. Therefore, increasing semen quality is an important means to improve the reproductive performance in swine industry. In this research review, we used the PubMed database and Google Scholar and web of science to search for relevant literature on the topic of AOS in relation to boar semen quality. Key words used were alginate oligosaccharide, boars, semen quality, microbiota and metabolites. The purpose of this review article was to describe the current knowledge on the relationship between AOS and boar semen quality, and provide an overview of solutions for the decline in the boar semen quality in specific conditions. Based on the existing literature, it is evident that AOS can be used as a new type of food additive. This review paper provides a theoretical basis for the production of high-quality boar sperm and, suggests that, in the future, AOS can even aid in treating human infertility.

Swine fertility in a changing climate

Climate change has been linked to increasing temperatures and weather extremes. Certain regions around the world become more susceptible to environmental hazards that limit pig production and reproductive fertility. Environmental measures that link to pig fertility are needed to assess change, risk and develop solutions. Sub-populations of pigs display lower fertility in summer and are susceptible to heat stress. In the context of a warming climate, elevated temperatures and number of heat stress days increase body temperature and change the physiology, behavior, feed intake, and stress response of the pig. These changes could alter follicle development, oocyte quality, estrus expression, conception and litter size. In boars, sperm quality and production are reduced in response to summer heat stress. Nevertheless, while temperature increases have occurred over the years in some warmer locations, other regions have not shown those changes. Perhaps this involves the measures used for heat stress assessment or that climate is buffered in more temperate areas. Reductions in pig fertility are not always evident, and depend upon climate, year, genotype and management. This could also involve selection, as females more susceptible to heat stress and fertility failure, are subsequently culled. In the years from 1999 to 2020 when increases in global temperature from baseline occurred, measures of female fertility improved for farrowing rate and litter size. Progressive reduction in fertility may not be apparent in all geo-locations, but as temperatures increases become more widespread, these changes are likely to become more obvious and detectable.

Assessing the antiviral activity of antimicrobial peptides Caerin1.1 against PRRSV in Vitro and in Vivo

The Porcine reproductive and respiratory syndrome (PRRS) causes severe financial losses to the global swine industry. Due to continuous virus evolution, the protection against the PRRS provided by current vaccines is limited. In order to find new antiviral strategies, this study investigated the antiviral potential of antimicrobial peptides (AMPs) against PRRSV. Given the diversity of PRRSV strains and the limited effectiveness of existing vaccines in controlling PRRSV, this study evaluated the inhibitory effects of KLAK, Cecropin B, Piscidin1, and Caerin1.1 on 3 strains of PRRSV (lineage 5 classical strain, lineage 8 highly pathogenic strain, and lineage 1 NADC30-like strain). Caerin1.1 exhibited significant dose-dependent antiviral activity, with an effective concentration (EC50) of 7.5 μM. Caerin1.1 effectively inhibited PRRSV replication when added before or in early infection but showed reduced effectiveness when added in late infection, indicating its potential involvement in targeting early transcription mechanisms of viral RNA polymerase and significantly upregulating cytokine gene expression. In the NADC30 strain-based animal infection model, Caerin1.1 treatment significantly reduced lung viral loads and inflammation in the lungs of PRRSV-infected pigs, with a mortality rate of 0 % (0/5) in the treated group compared to 66.67 % (4/6) in the untreated group, indicating a reduction in the mortality rate. Additionally, compared with the untreated group, the Caerin1.1-treated group showed significant improvements, such as lighter fever, more daily weight gain, less clinical symptoms, less viral load in blood, and less virus oral shedding (P < 0.05). These findings reveal the potential of antimicrobial peptides as PRRSV therapeutic agents and suggest that Caerin1.1 is a promising candidate for a novel anti-PRRSV drug.

Dynamic of swine influenza virus infection in weaned piglets in five enzootically infected herds in Germany, a cohort study

BACKGROUND

Within the last decades industrial swine herds in Europe grown significantly, creating an optimized reservoir for swine influenza A viruses (swIAV) to become enzootic, particularly in piglet producing herds among newborn, partly immunologically naïve piglets. To date, the only specific control measure to protect piglets from swIAV is the vaccination of sows, which provides passive immunity through maternally derived antibodies in colostrum of vaccinated sows. Interruption of infection chains through management practices have had limited success. This study focused on weaned piglets in five enzootically swIAV infected swine herds in North-West and North-East Germany and aimed to better understand swIAV infection patterns to improve piglet protection and reduce zoonotic risks. Participating farms fulfilled the following inclusion criteria: sow herd with ≥ 400 sows (actual size 600-1850 sows), piglets not vaccinated against influenza A virus and a history of recurrent respiratory problems associated with continuing influenza A virus infection. Influenza vaccination was performed in all sow herds, except for one, which discontinued vaccination during the study.

RESULTS

First swIAV detections in weaned piglets occurred at 4 weeks of age in the nursery and continued to be detected in piglets up to 10 weeks of age showing enzootic swIAV infections in all herds over the entire nursery period. This included simultaneous circulation of two subtypes in a herd and co-infection with two subtypes in individual animals. Evidence for prolonged (at least 13 days) shedding was obtained in one piglet based on two consecutive swIAV positive samplings. Possible re-infection was suspected in twelve piglets based on three samplings, the second of which was swIAV negative in contrast to the first and third sampling which were swIAV positive. However, swIAV was not detected in nasal swabs from either suckling piglets or sows in the first week after farrowing.

CONCLUSIONS

Predominantly, weaned piglets were infected. There was no evidence of transmission from sow to piglet based on swIAV negative nasal swabs from sows and suckling piglets. Prolonged virus shedding by individual piglets as well as the co-circulation of different swIAV subtypes in a group or even individuals emphasize the potential of swIAV to increase genetic (and potentially phenotypic) variation and the need to continue close monitoring. Understanding the dynamics of swIAV infections in enzootically infected herds has the overall goal of improving protection to reduce economic losses due to swIAV-related disease and consequently to advance animal health and well-being.

Artificial insemination and optimization of the use of seminal doses in swine

The optimization of processes associated with artificial insemination (AI) is of great importance for the success of the pig industry. Over the last two decades, great reproductive performance has been achieved, making further significant progress limited. Optimizing the AI program, however, is essential to the pig industry's sustainability. Thus, the aim is not only to reduce the number of sperm cells used per estrous sow but also to improve some practical management in sow farms and boar studs to transform the high reproductive performance to a more efficient program. As productivity is mainly influenced by the number of inseminated sows, guaranteeing a constant breeding group and with healthy animals is paramount. In the AI studs, all management must ensure conditions to the health of the boars. Some strategies have been proposed and discussed to achieve these targets. A constant flow of high-quality and well-managed breeding groups, quality control of semen doses produced, more reliable technology in the laboratory routine, removal of less fertile boars, the use of intrauterine AI, the use of a single AI with control of estrus and ovulation (fixed-time AI), estrus detection based on artificial intelligence technologies, and optimization regarding the use of semen doses from high genetic-indexed boars are some strategies in which improvement is sought. In addition to these new approaches, we must revisit the processes used in boar studs, semen delivery network, and sow farm management for a more efficient AI program. This review discusses the challenges and opportunities in adopting some technologies to achieve satisfactory reproductive performance and efficiency.

Boar semen cryopreservation: State of the art, and international trade vision

Biosecurity is a major concern in the global pig production. The separation in time of semen collection, processing and insemination in the pig farm is a few days for chilled semen but it can be indefinite when using cryopreserved semen. Field fertility results of boar cryopreserved semen are close to chilled semen, which makes it a valuable resource for the establishment of semen genebanks, long-distance semen trade, and the implementation of other technologies such as the sex-sorted semen. But cryopreserved semen is far from being routine in pig farms. The most recent research efforts to facilitate its implementation include the use of additives before freezing, or in the thawing extender. Long-term preserved semen trade is a biosecurity challenge. To harmonize international trade of germplasm, the World Organization of Animal Health (WOAH) established a regulatory framework for all member countries. The present paper aims to review the latest advances of boar semen cryopreservation with special focus on the benefits of its inclusion as a routine tool in the pig industry. We also review recently reported field fertility results of cryopreserved semen, its international trade compared to chilled semen, and the regulatory framework involved. Boar cryopreserved semen is a valuable tool to control biosecurity risk, implement other technologies, and facilitate international trade. Research already demonstrated good field fertility results, but it still represents less than 0.1 % of the international trade. As boar cryopreserved semen gets closer to implementation, the correspondent authorities are reviewing the trade rules.

Contaminant toxicity of concern for boars and semen used in assisted reproduction programs

The commercial swine industry utilizes artificial insemination (AI) in their breeding programs. With this assisted reproductive technology, the process starts by obtaining fresh ejaculates from desirable boars who are housed in a dedicated facility (i.e., stud) that also contains a clean-room laboratory where semen quality is assessed and then ejaculates processed into AI doses. In concert with AI adoption, disruptions in sow herd reproductive performance have been traced back to contributions made from the boar stud. Through field investigations and research, several extrinsic contaminants have been identified that impact semen quality either at the boar or AI-dose level. These contaminants can be categorized as either biological or chemical in origin, eliciting reprotoxic outcomes at the boar level and/or spermatotoxicity at the AI-dose level. Biological contaminants include multiple genera of primarily opportunistic microbes (i.e., bacteria, fungi), along with their secondary metabolites (e.g., endotoxins, exotoxins, mycotoxins). Chemical contaminants appear to originate from products used at the stud, and include cleaning agent/disinfectant residues, leachates from gloves and plastics, semen extender impurities, purified and drinking water impurities, and pesticides (i.e., biocides, fungicides, herbicides, insecticides, wood preservatives). In conclusion, contaminants are a real and constant threat to the health and productivity of a stud, and have caused significant reproductive and economic losses in the swine industry. The knowledge gained in recognizing the types and sources of contaminants provides a solid foundation for the development and implementation of pro-active strategies that mitigate risk to the industry.

Boar semen storage at 5 °C for the reduction of antibiotic use in pig insemination: Pathways from science into practice

Storage of boar semen at 5 °C instead of the conventional temperature of 17 °C is an innovative preservation concept. It enhances protection against the growth of bacteria normally occurring in the ejaculates and potential drug-resistant contaminants from the environment. Thereby it allows the reduction or even elimination of antibiotics in porcine semen extenders. The present article reviews the current state of the low-temperature preservation approach of boar semen, with a special focus on antimicrobial efficiency and fertility in field insemination trials. Particularly the role of semen extenders and temperature management for the achievement of high fertility and biosecurity are elucidated. Insemination data of 1,841 sows in there different countries revealed equally high farrowing rates and litter sizes of semen stored at 5 °C compared to the controls stored at 17 °C. Microbiology data obtained from semen doses spiked with multi-drug resistant bacteria showed the efficiency of the cold semen storage for inhibiting the growth of Serratia marcescens, a bacterial species with high sperm-toxicity. Evolving concepts on the physiological role of the male reproductive microbiome for female fertility provides a further argument against the complete eradication of bacteria in the semen dose by antibiotic additives to the extenders. Finally, motivation and practical considerations for the use of the novel preservation tool in artificial insemination of pigs are revealed, which might encourage the transformation towards a sustainable production of boar semen doses following the One Health approach.

Field efficacy of a recombinant toxoid vaccine against Shiga toxin 2e during a naturally occurring edema disease infection

The objective of this field trial was to determine the efficacy of a recombinant toxoid vaccine against Shiga toxin 2e (Stx2e) in piglets suffering from edema disease (ED). Three farms with confirmed ED cases were selected for the field trials. On each farm, a total of 40 4-day-old pigs were randomly allocated to either the vaccinated or unvaccinated group, with 20 pigs per group (10 males and 10 females). A 1.0-mL dose of the recombinant toxoid vaccine was administered intramuscularly to pigs in the vaccinated groups in accordance with the manufacturer's recommendations at 4 d of age. A single 2.0-mL dose of phosphate-buffered saline was administered to unvaccinated pigs at the same age. Clinical signs of ED were observed in 12 piglets in the unvaccinated groups and 7 unvaccinated pigs died as a result of ED out of the total number of piglets on Farms A, B, and C. Vaccination had a positive effect on pig growth performance compared to that of unvaccinated pigs on 2 of the 3 farms. Seroconversion of neutralizing antibodies against Stx2e occurred in 70% of piglets in the vaccinated group on Farm A, 75% of vaccinated piglets on Farm B, and 55% of vaccinated piglets on Farm C, when detectable antibodies were measured at 17 d post-vaccination (dpv). Detectable antibodies were measured in 85% of vaccinated piglets on Farms A and B and in 90% of these piglets on Farm C at 37 dpv. These field trials determined that the ED recombinant toxoid vaccine successfully reduced clinical signs and mortality, improved average daily weight gain, and resulted in the production of neutralizing antibodies against Stx2e in pigs.

Peri-implantitis with a potential axis to brain inflammation: an inferential review

Peri-implantitis (PI) is a chronic, inflammatory, and infectious disease which affects dental implants and has certain similarities to periodontitis (PD). Evidence has shown that PD may be related to several types of systemic disorders, such as diabetes and insulin resistance, cardiovascular diseases, respiratory tract infections, adverse pregnancy outcomes, and neurological disorders. Furthermore, some types of bacteria in PD can also be found in PI, leading to certain similarities in the immunoinflammatory responses in the host. This review aims to discuss the possible connection between PI and neuroinflammation, using information based on studies about periodontal disorders, a topic whose connection with systemic alterations has been gaining the interest of the scientific community. Literature concerning PI, PD, and systemic disorders, such as neuroinflammation, brain inflammation, and neurological disorder, was searched in the PubMed database using different keyword combinations. All studies found were included in this narrative review. No filters were used. Eligible studies were analyzed and reviewed carefully. This study found similarities between PI and PD development, maintenance, and in the bacterial agents located around the teeth (periodontitis) or dental implants (peri-implantitis). Through the cardiovascular system, these pathologies may also affect blood-brain barrier permeability. Furthermore, scientific evidence has suggested that microorganisms from PI (as in PD) can be recognized by trigeminal fiber endings and start inflammatory responses into the trigeminal ganglion. In addition, bacteria can traverse from the mouth to the brain through the lymphatic system. Consequently, the immune system increases inflammatory mediators in the brain, affecting the homeostasis of the nervous tissue and vice-versa. Based on the interrelation of microbiological, inflammatory, and immunological findings between PD and PI, it is possible to infer that immunoinflammatory changes observed in PD can imply systemic changes in PI. This, as discussed, could lead to the development or intensification of neuroinflammatory changes, contributing to neurodegenerative diseases.

Artificial intelligence and porcine breeding

Livestock management is evolving into a new era, characterized by the analysis of vast quantities of data (Big Data) collected from both traditional breeding methods and new technologies such as sensors, automated monitoring system, and advanced analytics. Artificial intelligence (A-In), which refers to the capability of machines to mimic human intelligence, including subfields like machine learning and deep learning, is playing a pivotal role in this transformation. A wide array of A-In techniques, successfully employed in various industrial and scientific contexts, are now being integrated into mainstream livestock management practices. In the case of swine breeding, while traditional methods have yielded considerable success, the increasing amount of information requires the adoption of new technologies such as A-In to drive productivity, enhance animal welfare, and reduce environmental impact. Current findings suggest that these techniques have the potential to match or exceed the performance of traditional methods, often being more scalable in terms of efficiency and sustainability within the breeding industry. This review provides insights into the application of A-In in porcine breeding, from the perspectives of both sows (including welfare and reproductive management) and boars (including semen quality and health), and explores new approaches which are already being applied in other species.

Modern feeding strategies for breeding boars

Feeding of breeding boars in artificial insemination (AI) centers is critical to maintaining and improving breeding quality and performance in agriculture. Modern feeding strategies for AI boars are aiming towards maximizing their lifetime semen dose output. Given the high growth potential of modern swine genetics, AI boars should be controlled in their daily gain to reduce stress factors for the locomotion system, final body weights, and improve their survivability but also the ease of handling boars. The feeding program should be designed in such a way that young boars (up to 7 months of age) are limited to a daily gain of 400-600 g. Mature boars should be fed towards a body condition score of '2'. Aside from energy intake, protein sources should provide 0.62% SID lysine. As far as minerals and vitamins, special attention should be given to Calcium and Phosphorus as they play a crucial role in bone mineralization. A standardized total tract digestible Calcium-Phosphorus ratio between 1.75:1 and 1.82:1 seems to be most favorable. While certain nutritional requirements are needed to enable the production of ejaculates eligible for AI, considerations should be given to the mitigation of risk factors like mycotoxins, herbicides, and pesticides. Most feed additives and supplements lack consistency in their effect across studies evaluated in this review.

Effects, methods and limits of the cryopreservation on mesenchymal stem cells

Mesenchymal stem cells (MSCs) are a type of cell capable of regulating the immune system, as well as exhibiting self-renewal and multi-lineage differentiation potential. Mesenchymal stem cells have emerged as an essential source of seed cells for therapeutic cell therapy. It is crucial to cryopreserve MSCs in liquid nitrogen prior to clinical application while preserving their functionality. Furthermore, efficient cryopreservation greatly enhances MSCs' potential in a range of biological domains. Nevertheless, there are several limits on the MSC cryopreservation methods now in use, necessitating thorough biosafety assessments before utilizing cryopreserved MSCs. Therefore, in order to improve the effectiveness of cryopreserved MSCs in clinical stem cell treatment procedures, new technological techniques must be developed immediately. The study offers an exhaustive analysis of the state-of-the-art MSC cryopreservation techniques, their effects on MSCs, and the difficulties encountered when using cryopreserved MSCs in clinical applications.

Prevalence, antimicrobial resistance, and genomic characterization of Salmonella strains isolated in Hangzhou, China: a two-year study

This study explored the molecular epidemiology and resistance mechanisms of 271 non-duplicate Salmonella enterica (S. enterica) strains, isolated mainly from adults (209/271) in a tertiary hospital in Hangzhou between 2020 and 2021. Through whole-genome sequencing and bioinformatics, the bacterial strains were classified into 46 serotypes and 54 sequence types (ST), with S. Enteritidis, S. 1,4,[5],12:i:-, and S. Typhimurium being the most prevalent serotypes and ST11, ST34, and ST19 the most common STs. The strains isolated from adults were primarily S. Enteritidis (59/209), while from children were mainly S. 1,4,[5],12:i:- (20/62). Worryingly, 12.55% strains were multi-drug resistant (MDR), with resistance rates to cefepime (FEP), ceftazidime (CAZ), ceftriaxone (CRO) and cefotaxime (CTX) of 7.38%, 9.23%, 15.87% and 16.24%, respectively, and resistance rates to levofloxacin (LEV) and ciprofloxacin (CIP) of 8.49% and 19.19%, respectively. It is worth noting that the resistance rates of CRO and CTX in children reached 30.65%. A total of 34 strains carried extended-spectrum β-lactamase (ESBL) genes, dominated by blaCTX-M-65 (13/34) and blaCTX-M-55 (12/34); it is notable that one strain of S. Saintpaul carried both blaCTX-M-27 and blaCTX-M-55. The resistance mechanism to cephalosporins was mainly due to ESBL genes (20/43), and other genes included AmpC and β-lactamase genes. The strains resistant to quinolones mainly carried qnrS1 (27/53), and others included qnrB6, aac(6')-Ib-cr, and mutations in gyrA and parC. One strain did not carry common quinolone resistance genes but had a parC (p.T57S) mutation to cause CIP resistance. This research provides vital insights into the molecular epidemiology and resistance mechanisms of clinical S. enterica, implicating possible infection control strategies.

Epidemiological investigation and analysis of the infection of porcine circovirus in Xinjiang

Porcine circoviruses, particularly porcine circovirus type 2 (PCV2) and porcine circovirus type 3 (PCV3), significantly impact the global pig industry due to their high prevalence and pathogenicity. Conversely, porcine circovirus type 1 (PCV1) and porcine circovirus type 4 (PCV4) currently have low positivity rates. This study aimed to characterize the distribution and epidemiology of porcine circoviruses in Xinjiang, while also analyzing the genetic diversity and evolution of PCV2 and PCV3, which pose the greatest threats to the industry. In this study, we collected blood and tissue samples from 453 deceased pigs across eight regions in Xinjiang Province from 2022 to 2024. We utilized real-time PCR to detect the presence of PCV1, PCV2, PCV3, and PCV4. The positive rates were 15%, 71%, 25%, and 17%, respectively. Genetic analysis showed 9 PCV2 sequences and 12 PCV3 sequences. The capsid protein of PCV2 showed significant variability. In contrast, the amino acid sequences of capsid in PCV3 were relatively stable. Moreover, we predicted antigenic epitopes for PCV3 capsid using IEDB and ElliPro. The findings from this study provide valuable epidemiological data on PCV coinfection in the Xinjiang region and enhance the understanding of virus diversity nationwide. This research may serve as an important reference for the development of strategies to prevent and control porcine circovirus infections.

Value creation of copra meal mannan into functional manno-oligosaccharides (β-MOS) using the mannanase Bacillus man B (BlMan26B)

Agricultural wastes rich in β-mannan are an important environmental problem in tropical and sub-tropical countries. This research aims at dealing with this and investigates the valorization of mannan-rich copra meal from virgin coconut oil manufacturing into mannan-oligosaccharides (β-MOS) by enzymatic hydrolysis using β-mannanase from Bacillus licheniformis (BlMan26B). Lab-scale process, involving pre-treatment and bioconversion steps, were conducted and evaluated. Lyophilized β-MOS was analyzed and its biological activities were assessed. The size of oligosaccharides obtained ranged from dimers to hexamers with 36.7% conversion yields. The prebiotic effects of β-MOS were demonstrated in comparison with commercial inulin and fructo-oligosaccharides (FOS). In vitro toxicity assays of β -MOS on human dermal fibroblasts and monocytes showed no cytotoxic effect. Interestingly, β-MOS at concentrations ranging from 10 to 200 µg/mL also demonstrated potent anti-inflammatory activity against LPS-induced inflammation of human macrophage THP-1 in a dose-dependent manner. However, at high dose, β-MOS could also stimulate inflammation. Therefore, further investigation must be conducted to ensure its efficacy and safe use in the future. These results indicate that β-MOS have the potential to be used as valued-added health-promoting nutraceutical or feed additive after additional in-depth studies. These finding should be applicable for other agricultural wastes rich in mannan as well.

Genetic characteristics associated with the virulence of porcine epidemic diarrhea virus (PEDV) with a naturally occurring truncated ORF3 gene

Porcine epidemic diarrhea virus (PEDV) has emerged in American countries, and it has reemerged in Asia and Europe, causing significant economic losses to the pig industry worldwide. In the present study, the 17GXCZ-1ORF3d strain, which has a naturally large deletion at the 172-554 bp position of the ORF3 gene, together with the 17GXCZ-1ORF3c strain, was serially propagated in Vero cells for up to 120 passages. The adaptability of the two strains gradually increased through serial passages in vitro. Genetic variation analysis of the variants of the two strains from different generations revealed that the naturally truncated ORF3 gene in the 17GXCZ-1ORF3d variants was stably inherited. Furthermore, the survival, viral shedding and histopathological lesions following inoculation of piglets demonstrated that the virulence of 17GXCZ-1ORF3d-P120 was significantly attenuated. These results indicate that the naturally truncated ORF3 gene may accelerate the attenuation of virulence and is involved in PEDV virulence together with mutations in other structural genes. Importantly, immunization of sows with G2b 17GXCZ-1ORF3d-P120 increased PEDV-specific IgG and IgA antibody levels in piglets and conferred partial passive protection against heterologous G2a PEDV strains. Our findings suggest that an attenuated strain with a truncated ORF3 gene may be a promising candidate for protection against PEDV.

Assessment of real-time PCR test in oral fluid samples for screening the serotypes of Actinobacillus pleuropneumoniae circulating in swine herds

Actinobacillus pleuropneumoniae is the etiological agent of porcine pleuropneumonia, causing remarkable economic losses in the global swine industry. The diversity of A. pleuropneumoniae is generally determined through serotype identification, which is commonly employed for control strategies and surveillance. However, serological methods currently in use still have significant limitations. This study explores the use of real-time polymerase chain reaction (qPCR) to detect circulating serotypes of A. pleuropneumoniae in non-diseased swine herds through testing of oral fluids. The study included three A. pleuropneumoniae-positive and three A. pleuropneumoniae-negative farms located in Quebec, Canada. Tonsil brushings, microbiological growths, and oral fluids were analyzed using qPCR to detect A. pleuropneumoniae and its distinct serotypes. Serological tests were performed using the LPS ELISA available at that time. In negative farms the absence of A. pleuropneumoniae and any serotype confirmed the specificity of the method. Positive farms, on the other hand, confirmed also the sensitivity of the analysis, with oral fluid samples consistently yielding positive results for the serotypes identified by ELISA. The qPCR test conducted on oral fluids offers a noninvasive and cost-effective method for monitoring, complementing traditional serological techniques. It provides qualitative information about serotype distribution, facilitating proactive surveillance and control strategies.

Screening and identification of linear B-cell epitopes on structural proteins of African Swine Fever Virus

This study aims to screen and identify linear B-cell epitopes on the structural proteins of African Swine Fever Virus (ASFV) to assist in the development of peptide-based vaccines. In experiments, 66 peptides of 12 structural proteins of ASFV were predicted as potential linear B-cell epitopes using bioinformatics tools and were designed; the potential epitope proteins carried the GST tag were expressed, purified, and subjected to antigenicity analysis with porcine antiserum against ASFV, and further identified based on their immunogenicity in mice. A total of 22 potential linear B-cell epitopes showed immunoreactivity and immunogenicity. Of these epitopes, 13 epitopes were firstly identified including 4 epitopes located in p72 (352-363, 416-434, 424-439, 496-530 aa), 3 epitopes located in pE248R (121-136, 138-169, 158-185 aa), and only one epitope of each protein of pH108R (33-46 aa), p17 (63-86 aa), pE120R (65-117 aa), pE199L (175-189 aa), p12 (36-56 aa) as well as pB438L (211-230 aa). Notably, the immunoreactivity of the epitopes from the 63-86 aa of p17 and the 65-117 aa of pE120R were the highest amongst identified epitopes, while the immunogenicity of epitopes from the 36-56 aa of p12, the 211-230 aa of pB438L, the 352-363 aa of p72 and the 63-86 aa of p17 were the best strong. The other 9 epitopes are partly overlapped with previous researches. These epitopes identified here will further enrich the database of ASFV epitope, as well as help to develop safe, effective epitope-based ASF vaccines and ASF diagnostic reagents.

Navigating the threat of African swine fever: a comprehensive review

African swine fever (ASF) is caused by Asfivirus and has become one of the most important diseases of swine in recent years. ASF was an endemic disease of the sub-Saharan Africa but later spread to various parts of the world. The infection in ticks and wild swine, alongside global pork trade, drives its spread and persistence. Once introduced to an area, the disease is difficult to eliminate due to sylvatic, domestic, and tick-swine transmission cycles. Because of the existence of various modes of transmission of the ASF virus, biosecurity measures have not been very successful. The line of treatment is not of much use and the outcome of this disease is usually fatal. The prognosis or the recovery of the animal depends on the virulence of the strain involved. Development of vaccines has been attempted but to date has not been very successful. This review focuses on the basic context of ASF, the challenges associated with it, and the options that might be available to prevent its occurrence which includes the different vaccine development strategies tried and tested till now.

Identification of linear B-cell epitope on the structure protein p49 of African Swine Fever Virus (ASFV)

African swine fever (ASF), a viral disease affecting both domestic pigs and wild boars, is caused by the African swine fever virus (ASFV). Currently, an effective vaccine is lacking. The structural protein p49, encoded by the B438L gene, is vital for the virus's capsid structure and architecture. Research indicates its potential as a vaccine target. In this study, mAbs against ASFV p49 were generated using the hybridoma technique. The full-length B438L sequence was divided into 5 segments (B1 ∼ B5) via the overlapping polypeptide method, and an expression vector was constructed for expression and purification. Three hybridoma cell lines recognized epitope regions, with 3B12 and 6F1 recognizing the B4 (aa 234-362) fragment, and 3B12, 6F1, and 7C5 reacting with the B5 (aa 312-438) segment. The amino acid sequence (aa 333-438) was further divided into three segments (B6 ∼ B8) for verification. Results from Dot-ELISA and peptide ELISA confirmed that 333-YQTHYMENIVTLVPR-347 and 383-NNYIPKYTGGIGDSK-397 were the major B cell antigenic, highly conserved across ASFV strains. Interestingly, the motif 333-YQTHYMENIVTLVPR-347 was highly conserved, except for a single substitution (T → S) in three residues. This study identifies the B cell epitope of p49 protein, providing insights into ASFV p49 protein structure and function and supporting the development of ASFV-related vaccine products.

Making the invisible visible: Effectiveness of a training program to increase awareness and biosecurity compliance in poultry barn anterooms, using glowing substances

Biosecurity is the cornerstone of prevention strategies to limit infectious pathogen spread between poultry farms. However, poor compliance of biosecurity measures is often observed when entering or exiting barns. The lack of knowledge, understanding, risk perception or technical skill are often described for anteroom-related biosecurity errors (i.e., not respecting anteroom zoning in relation to changing boots, clothing, and hand sanitation). In this study, we designed and assessed the efficacy of an intervention aiming at improving biosecurity compliance in anterooms, using substances glowing under ultraviolet light, which mimic microbiological contamination. Training exercises offered in a single session were proposed to 145 participants with an interest in animal farming (veterinary students, agricultural students, poultry farmers and poultry farm advisors). The exercises' efficacy was assessed by measuring the change in attitude and intentions of participants about specific biosecurity measures. The participants' attitudes and intentions were quantified using a questionnaire before and after training. The change in score was assessed in a multivariate linear regression model to measure the effect of various parameters on this change. The attitudes and intentions of participants were statistically improved (p < 0.05) and were affected by the initial attitude and intention score, the gender of the participants and the status of the participant (type of student or activity in the poultry industry). The use of this exercise material, perceived as playful and engaging, could be included in the framework of biosecurity training for all stakeholders of the poultry industry.

Wild Boar Proves High Tolerance to Human-Caused Disruptions: Management Implications in African Swine Fever Outbreaks

Currently, African swine fever (ASF), a highly fatal disease has become pervasive, with outbreaks recorded across European countries, leading to preventative measures to restrict wild boar (Sus scrofa L.) movement, and, therefore, keep ASF from spreading. This study aims to detail how specific human activities-defined as "car", "dog", "chainsaw", and "tourism"-affect wild boar behavior, considering the disturbance proximity, and evaluate possible implications for wild boar management in ASF-affected areas. Wild boar behavior was studied using advanced biologging technology. This study tracks and analyzes wild boar movements and behavioral responses to human disturbances. This study utilizes the dead reckoning method to precisely reconstruct the animal movements and evaluate behavioral changes based on proximity to disturbances. The sound of specific human activities was reproduced for telemetered animals from forest roads from different distances. Statistical analyses show that wild boars exhibit increased vigilance and altered movement patterns in response to closer human activity, but only in a small number of cases and with no significantly longer time scale. The relative representation of behaviors after disruption confirmed a high instance of resting behavior (83%). Running was the least observed reaction in only 0.9% of all cases. The remaining reactions were identified as foraging (5.1%), walking (5.0%), standing (2.2%), and other (3.8%). The findings suggest that while human presence and activities do influence wild boar behavior, adherence to movement restrictions and careful management of human activity in ASF-infected areas is not a necessary measure if human movement is limited to forest roads.

RNA-Seq Analysis Revealed circRNAs Associated with Resveratrol-Induced Apoptosis of Porcine Ovarian Granulosa Cells

Circular RNAs (circRNAs) are a class of circular non-coding RNAs that play essential roles in the intricate and dynamic networks governing cell growth, development, and apoptosis. Resveratrol (RSV), a non-flavonoid polyphenol, is known to participate in follicular development and ovulation. In our previous research, we established a model using porcine ovarian granulosa cells (POGCs) treated with resveratrol, which confirmed its regulatory effects on long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) within these cells. However, the influence of resveratrol on circRNA expression has not been thoroughly investigated. To explore how resveratrol affects circRNA levels in POGCs, we designed an experiment with three groups: a control group (CON, n = 3, 0 μM RSV), a low-dose RSV group (LOW, n = 3, 50 μM RSV), and a high-dose RSV group (HIGH, n = 3, 100 μM RSV) for circRNA sequencing. We identified a total of 10,045 candidate circRNAs from POGCs treated with different concentrations of resveratrol (0, 50, and 100 μM). Differential expression analysis indicated that 96 circRNAs were significantly altered in the LOW vs. CON group, while 109 circRNAs showed significant changes in the HIGH vs. CON group. These circRNAs were notably enriched in biological processes associated with cell metabolism, apoptosis, and oxidative stress. Functional enrichment analysis of the host genes revealed their involvement in critical signaling pathways, including mTOR, AMPK, and apoptosis pathways. Additionally, we identified potential miRNA sponge candidates among the differentially expressed circRNAs, particularly novel_circ_0012954 and novel_circ_0004762, which exhibited strong connectivity within miRNA-target networks. Our findings provide valuable insights into the regulatory mechanisms of circRNAs in the context of resveratrol-induced apoptosis in POGCs, highlighting their potential as innovative therapeutic targets in reproductive biology.

A genome assembly and transcriptome atlas of the inbred Babraham pig to illuminate porcine immunogenetic variation

The inbred Babraham pig serves as a valuable biomedical model for research due to its high level of homozygosity, including in the major histocompatibility complex (MHC) loci and likely other important immune-related gene complexes, which are generally highly diverse in outbred populations. As the ability to control for this diversity using inbred organisms is of great utility, we sought to improve this resource by generating a long-read whole genome assembly and transcriptome atlas of a Babraham pig. The genome was de novo assembled using PacBio long reads and error-corrected using Illumina short reads. Assembled contigs were then mapped to the porcine reference assembly, Sscrofa11.1, to generate chromosome-level scaffolds. The resulting TPI_Babraham_pig_v1 assembly is nearly as contiguous as Sscrofa11.1 with a contig N50 of 34.95 Mb and contig L50 of 23. The remaining sequence gaps are generally the result of poor assembly across large and highly repetitive regions such as the centromeres and tandemly duplicated gene families, including immune-related gene complexes, that often vary in gene content between haplotypes. We also further confirm homozygosity across the Babraham MHC and characterize the allele content and tissue expression of several other immune-related gene complexes, including the antibody and T cell receptor loci, the natural killer complex, and the leukocyte receptor complex. The Babraham pig genome assembly provides an alternate highly contiguous porcine genome assembly as a resource for the livestock genomics community. The assembly will also aid biomedical and veterinary research that utilizes this animal model such as when controlling for genetic variation is critical.

Nutraceuticals and pharmacological to balance the transitional microbiome to extend immunity during COVID-19 and other viral infections

SCOPE

The underlying medical conditions and gut dysbiosis is known to influence COVID-19 severity in high-risk patients. The current review proposed the optimal usage of nutraceuticals & pharmacological interventions can help regulate the protective immune response and balance the regulatory functionality of gut microbiota. Many studies have revealed that the probiotic interventions viz., Lactobacillus rhamnosus, L. plantarum & other bacterial spp. reduce IFNγ & TNF-α and increase IL-4 & IL-10 secretions to control the immunostimulatory effects in upper respiratory tract infection. Dietary fibres utilized by beneficial microbiota and microbial metabolites can control the NF-kB regulation. Vitamin C halts the propagation of pathogens and vitamin D and A modulate the GM. Selenium and Flavonoids also control the redox regulations. Interferon therapy can antagonize the viral replications, while corticosteroids may reduce the death rates. BCG vaccine reprograms the monocytes to build trained immunity. Bifidobacterium and related microbes were found to increase the vaccine efficacy. Vaccines against COVID-19 and season flu also boost the immunity profile for robust protection. Over all, the collective effects of these therapeutics could help increase the opportunities for faster recovery from infectious diseases.

CONCLUSION

The nutraceutical supplements and pharmacological medicines mediate the modulatory functionalities among beneficial microbes of gut, which in turn eliminate pathogens, harmonize the activity of immune cells to secrete essential regulatory molecular receptors and adaptor proteins establishing the homeostasis in the body organs through essential microbiome. Therefore, the implementation of this methodology could control the severity events during clinical sickness and reduce the mortalities.

Food circular economy and safety considerations in waste management of urban manufacturing side streams

In food circular economy, the utilization of food manufacturing side streams (FMSS) offers significant potential instead of being discarded. However, reincorporating FMSS into the food value chain raises food safety concerns due to potential food hazards. This perspective explores food safety risks associated with circular management of FMSS by using a 'Quad-Modal hazard dynamic' approach with case studies. Future research and advancements in food safety control strategies are also discussed.

Infrared Thermography as a Diagnostic Tool for the Assessment of Mastitis in Dairy Ruminants

Among the health issues of major concern in dairy ruminants, mastitis stands out as being associated with considerable losses in productivity and compromised animal health and welfare. Currently, the available methods for the early detection of mastitis are either inaccurate, requiring further validation, or expensive and labor intensive. Moreover, most of them cannot be applied at the point of care. Infrared thermography (IRT) is a rapid, non-invasive technology that can be used in situ to measure udder temperature and identify variations and inconsistencies thereof, serving as a benchmarking tool for the assessment of udders' physiological and/or health status. Despite the numerous applications in livestock farming, IRT is still underexploited due to the lack of standardized operation procedures and significant gaps regarding the optimum settings of the thermal cameras, which are currently exploited on a case-specific basis. Therefore, the objective of this review paper was twofold: first, to provide the state of knowledge on the applications of IRT for the assessment of udder health status in dairy ruminants, and second, to summarize and discuss the major strengths and weaknesses of IRT application at the point of care, as well as future challenges and opportunities of its extensive adoption for the diagnosis of udder health status and control of mastitis at the animal and herd levels.

Sow reproductive performance following artificial insemination with semen doses processed using Single Layer Centrifugation without antibiotics in the tropics

Single Layer Centrifugation (SLC) through a low density colloid offers an alternative solution to antibiotic use in boar semen extenders, with lower costs compared to high density colloids. The aim of this study was to explore the reproductive performance of sows when using SLC-prepared semen doses without antibiotics, employing low density Porcicoll to prepare semen doses for artificial insemination in a commercial swine herd in Thailand. Ejaculates were divided into two equal parts to create insemination doses, with each dose containing 3000 × 106 sperm/80 ml for intra-uterine insemination in individual sows. The sows were inseminated twice, with the interval between the two inseminations ranging from 8 to 16 h. The CONTROL group consisted of 206 semen doses treated with antibiotics, prepared for insemination in 103 sows, while the SLC group comprised 194 SLC-prepared semen doses without antibiotics for inseminating 97 sows. Fertility and fecundity traits, including non-return rate, conception rate, farrowing rate, and litter traits (i.e., the total number of piglets born per litter, number of piglets born alive per litter, number of stillborn piglets, and number of mummified fetuses), were compared between groups. Furthermore, data on piglet characteristics, including live-born and stillborn piglets (i.e., the prevalence of stillbirth (yes, no), birth weight, crown-rump length, body mass index (BMI), and ponderal index (PI)), were determined. No significant differences in non-return rate (75.7 % vs. 77.3 %), conception rate (73.8 % vs. 73.2 %), and farrowing rate (71.8 % vs. 73.2 %) were observed between the CONTROL and SLC groups, respectively (P > 0.05). Nevertheless, the total number of piglets born per litter in the SLC group was higher than in the CONTROL group (14.6 ± 0.9 vs. 12.3 ± 0.6, respectively, P = 0.049). Interestingly, the prevalence of stillbirth in the SLC group was lower than in the CONTROL group (6.2 % vs. 11.6 %, respectively, P < 0.001). Moreover, the newborn piglets in the SLC group exhibited higher birth weight and BMI compared to those in the CONTROL group (1.36 ± 0.03 vs. 1.26 ± 0.02 kg, P = 0.005, and 18.3 ± 0.3 vs. 17.3 ± 0.2 kg/m2, P = 0.003). In conclusion, employing sperm doses after SLC through a low density colloid in artificial insemination within a commercial breeding operation did not have a detrimental impact on either fertility or fecundity traits but showed potential benefits in increasing the total number of piglets born per litter. Moreover, improvements were observed in the birth weight and body indexes of piglets, and the percentage of stillbirths was reduced. Our findings introduce new possibilities for antibiotic alternatives in semen extenders to reduce the risk of antimicrobial resistance in the swine industry. Additionally, they provide compelling reproductive outcomes supporting the integration of SLC-prepared semen doses into artificial insemination practices.

Preservation of agri-food byproducts by acidification and fermentation in black soldier fly larvae bioconversion

Maintaining a consistent supply of feedstock for efficient bioconversion of black soldier fly larvae (BSFL) presents challenges due to the fluctuating availability of biowastes and agri-food products. To address the challenge of consistent feedstock supply for BSFL, this study investigated the influence of three preservation methods: wild fermentation, inoculated fermentation, and acidification on agri-food by-products applied over three storage durations (1, 7, and 14 days), evaluating their impact on BSFL bioconversion, and feedstock nutrient and microbiota composition. The preserved feedstocks were characterized for gross nutrient, sugar, fermentation metabolite, and bacterial community analyses. All feedstock preservation methods and storage durations had a high bioconversion rate (21-25 % dry mass) and wet larval mass (170-196 mg). Notably, 7-and-14-day acidified feedstock had a significantly higher bioconversion rate compared to fermented feedstock. Acidification preserved feedstock nutrients best with only a 10 % difference compared to initial nutrient values. Fermentation produced typical lactic acid fermentation metabolites with reducing sugar contents; however, adding a lactic acid bacterial inoculum (7 log10 CFU kg feedstock-1) had no benefit, presumably due to the high nutrient content and existing richness in lactic acid bacteria. Preservations had little influence on Enterobacteriaceae (6.2-7.5 log10 CFU g-1) in freshly harvested larvae. Future research should assess the acidification and fermentation of different BSFL feedstocks and investigate the roles of feedstock pH, organic acids, and fermentation metabolites in more detail. Therefore, this study advances toward reliable and efficient insect-based nutrient recovery from agri-food by-products within the food system.

An effective vaccine against influenza A virus based on the matrix protein 2 (M2)

The ever-increasing antigenic diversity of the hemagglutinin (HA) of influenza A virus (IAV) poses a significant challenge for effective vaccine development. Notably, the matrix protein 2 (M2) is a highly conserved 97 amino acid long transmembrane tetrameric protein present in the envelope of IAV. More than 99 % of IAV strains circulating in American swine herds share the identical pandemic (pdm) isoform of M2, making it an ideal target antigen for a vaccine that could elicit broadly protective immunity. Here, using soluble nanoscale membrane assemblies termed nanodiscs (NDs), we designed this membrane mimetic nanostructures displaying full-length M2 in its natural transmembrane configuration (M2ND). Intramuscular (IM) immunization of swine with M2ND mixed with conventional emulsion adjuvant elicited M2-specific IgG antibodies in the serum that recognized influenza virions and M2-specific interferon-γ secreting cells present in the blood. Intranasal (IN) immunization with M2ND adjuvanted with a mycobacterial extract elicited M2-specific IgA in mucosal secretions that also recognized IAV. Immunization with an influenza whole inactivated virus (WIV) vaccine supplemented with a concurrent IM injection of M2ND mixed with an emulsion adjuvant increased the level of protective immunity afforded by the former against a challenge with an antigenically distinct H3N2 IAV, as exhibited by an enhanced elimination of virus from the lung. The lone IM administration of the M2ND vaccine mixed with an emulsion adjuvant provided measurable protection as evidenced by a >10-fold reduction or complete elimination of the challenge virus from the lung, but it did not diminish the viral load in nasal secretions nor the extent of pneumonia that ensued after the virus challenge. In contrast, an improved formulation of the M2ND vaccine that incorporated synthetic CpG oligodeoxynucleotides (CpG-ODN) in the nanostructures administered alone, via the IN and IM routes combined, provided a significant level of protective immunity against IAV as evidenced by a decreased viral load in both the upper and lower respiratory tracts and fully eliminated the occurrence of pneumonia in 89 % of the pigs immunized with this biologic. Notably, to be effective, the M2 protein must be displayed in the ND assemblies, as shown by the observation that simply mixing M2 with empty NDs incorporating CpG-ODN (eND-CpG-ODN) did not provide protective immunity. This novel M2-based vaccine offers great promise to help increase the breadth of protection afforded by conventional WIV vaccines against the diversity of IAV in circulation and, plausibly, as a broadly protective stand-alone biologic.