Swine Influenza Research Articles

MALDI-TOF nucleic acid mass spectrometry for simultaneously detection of fourteen porcine viruses and its application

BackgroundMixed infections of multiple viruses significantly contribute to the prevalence of swine diseases, adversely affecting global livestock production and the economy. However, effectively monitoring multiple viruses and detecting mixed infection samples remains challenging. This study describes a method that combines single-base extension PCR with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) to detect important porcine viruses. ResultsOur approach accurately and simultaneously identified 14 porcine viruses, including porcine circovirus types 1–3, porcine bocaviruses groups 1–3, African swine fever virus, pseudorabies virus, porcine parvovirus, torque teno sus virus, swine influenza virus, porcine reproductive and respiratory syndrome virus, classical swine fever virus, and foot-and-mouth disease virus. The low limit of detection for multiplex identification ranges from 13.54 to 1.59 copies/μL. Inter- and intra-assay stability was found to be ≥98.3 %. In a comprehensive analysis of 114 samples, the assay exhibited overall agreement with qPCR results of 97.9 %. ConclusionsThe developed MALDI-TOF NAMS assay exhibits high sensitivity, specificity, and reliability in detecting and distinguishing a wide spectrum of porcine viruses in complex matrix samples. This underscores its potential as an efficient diagnostic tool for porcine-derived virus surveillance and swine disease control.

Potential pandemic risk of circulating swine H1N2 influenza viruses

Influenza A viruses in swine have considerable genetic diversity and continue to pose a pandemic threat to humans due to a potential lack of population level immunity. Here we describe a pipeline to characterize and triage influenza viruses for their pandemic risk and examine the pandemic potential of two widespread swine origin viruses. Our analysis reveals that a panel of human sera collected from healthy adults in 2020 has no cross-reactive neutralizing antibodies against a α-H1 clade strain (α-swH1N2) but do against a γ-H1 clade strain. The α-swH1N2 virus replicates efficiently in human airway cultures and exhibits phenotypic signatures similar to the human H1N1 pandemic strain from 2009 (H1N1pdm09). Furthermore, α-swH1N2 is capable of efficient airborne transmission to both naïve ferrets and ferrets with prior seasonal influenza immunity. Ferrets with H1N1pdm09 pre-existing immunity show reduced α-swH1N2 viral shedding and less severe disease signs. Despite this, H1N1pdm09-immune ferrets that became infected via the air can still onward transmit α-swH1N2 with an efficiency of 50%. These results indicate that this α-swH1N2 strain has a higher pandemic potential, but a moderate level of impact since there is reduced replication fitness and pathology in animals with prior immunity.

Evaluation of Efficacy of Surface Coated versus Encapsulated Influenza Antigens in Mannose-Chitosan Nanoparticle-Based Intranasal Vaccine in Swine.

This study focuses on the development and characterization of an intranasal vaccine platform using adjuvanted nanoparticulate delivery of swine influenza A virus (SwIAV). The vaccine employed whole inactivated H1N2 SwIAV as an antigen and STING-agonist ADU-S100 as an adjuvant, with both surface adsorbed or encapsulated in mannose-chitosan nanoparticles (mChit-NPs). Optimization of mChit-NPs included evaluating size, zeta potential, and cytotoxicity, with a 1:9 mass ratio of antigen to NP demonstrating high loading efficacy and non-cytotoxic properties suitable for intranasal vaccination. In a heterologous H1N1 pig challenge trial, the mChit-NP intranasal vaccine induced cross-reactive sIgA antibodies in the respiratory tract, surpassing those of a commercial SwIAV vaccine. The encapsulated mChit-NP vaccine induced high virus-specific neutralizing antibody and robust cellular immune responses, while the adsorbed vaccine elicited specific high IgG and hemagglutinin inhibition antibodies. Importantly, both the mChit-NP vaccines reduced challenge heterologous viral replication in the nasal cavity higher than commercial swine influenza vaccine. In summary, a novel intranasal mChit-NP vaccine platform activated both the arms of the immune system and is a significant advancement in swine influenza vaccine design, demonstrating its potential effectiveness for pig immunization.

Large-Scale Serological Survey of Influenza A Virus in South Korean Wild Boar (Sus scrofa).

In this comprehensive large-scale study, conducted from 2015 to 2019, 7,209 wild boars across South Korea were sampled to assess their exposure to influenza A viruses (IAVs). Of these, 250 (3.5%) were found to be IAV-positive by ELISA, and 150 (2.1%) by the hemagglutination inhibition test. Detected subtypes included 23 cases of pandemic 2009 H1N1, six of human seasonal H3N2, three of classical swine H1N1, 13 of triple-reassortant swine H1N2, seven of triple-reassortant swine H3N2, and seven of swine-origin H3N2 variant. Notably, none of the serum samples tested positive for avian IAV subtypes H3N8, H5N3, H7N7, and H9N2 or canine IAV subtype H3N2. This serologic analysis confirmed the exposure of Korean wild boars to various subtypes of swine and human influenza viruses, with some serum samples cross-reacting between swine and human strains, indicating potential infections with multiple IAVs. The results highlight the potential of wild boar as a novel mixing vessel, facilitating the adaptation of IAVs and their spillover to other hosts, including humans. In light of these findings, we recommend regular and frequent surveillance of circulating influenza viruses in the wild boar population as a proactive measure to prevent potential human influenza pandemics and wild boar influenza epizootics.

Efficacy of oleandrin and PBI-05204 against viruses of importance to commercial pig health management

BackgroundInfection by porcine respiratory and reproductive syncytial virus (PRRSV), swine influenza virus (SIV) and porcine epidemic diarrhea (PEDV) adversely affect worldwide pig production. Because effective control remains elusive the present research was designed to explore the in vitro antiviral activity of oleandrin and an N. oleander extract (PBI-05204) against each porcine virus.MethodsMonkey kidney (MARK-145) cells, Madin-Darby canine kidney cells (MDCK), and African green monkey kidney cells (VERO 76) were used for in vitro culture systems for PRRSV, SIV and PEDV, respectively. Cytotoxicity was established using serial dilutions of oleandrin or PBI-05204. Noncytotoxic concentrations of each product were used either prior to or at 12 h and 24 h following exposure to corresponding viruses. Infectious virus titers were also determined.ResultsOleandrin and PBI-05204 demonstrated strong antiviral activity against PRRSV, SIV and PEDV when added prior to or following infection of cells. Determination of viral loads by PCR demonstrated a decline in PRRSV replication reaching 99.57% and 99.79% for oleandrin and PBI-05204, respectively, and decrease of 95.36% and 99.54% in infectivity of progeny virus in PRRSV infected cultures. Similarly, oleandrin tested against SIV and PEDV was effective in near complete inhibition of infectious virus production.ConclusionThe research demonstrates the potency of oleandrin and PBI-05204 to inhibit infectivity of three important porcine viruses. These data showing non-toxic concentrations of oleandrin as a single common agent for inhibiting infectivity of the three different porcine viruses tested here support further investigation of antiviral efficacy and possible in vivo use.

Molecular Detection of Porcine Cytomegalovirus, Porcine Parvovirus, Aujeszky Disease Virus and Porcine Reproductive and Respiratory Syndrome Virus in Wild Boars Hunted in Serbia during 2023.

Porcine cytomegalovirus (PCMV) infection is widespread worldwide and has a high prevalence in swine herds, especially in countries with intensive swine production. PCMV is zoonotic and can impact xenotransplants. It is the third swine virus known to be zoonotic, following swine influenza virus (influenza A) and hepatitis E virus genotype 3 (HEVgt3 or HEV-3). Wild boars, serving as reservoirs for various pathogens, including PCMV, pose a risk to both the pig industry and public health. This study aimed to investigate PCMV infection in Serbian wild boars using real-time PCR and assess other viral infections. We also tested samples for the presence of other viral infections: Aujeszky disease virus (ADV), Porcine parvovirus (PPV) and Porcine reproductive respiratory syndrome (PRRSV). Samples from 50 wild boars across 3 districts were tested. Results showed 8% positivity for PCMV DNA, with females showing higher infection rates. Porcine parvovirus (PPV) was detected in 56% of samples, while Porcine reproductive respiratory syndrome virus (PRRSV) was absent. ADV was found in 18% of samples, primarily in younger animals. This research contributes to understanding PCMV prevalence in Serbian wild boars and emphasizes the importance of monitoring viral infections in wild populations, considering the potential zoonotic and economic implications.

Emergence of Eurasian Avian-Like Swine Influenza A (H1N1) virus in a child in Shandong Province, China

BackgroundInfluenza A virus infections can occur in multiple species. Eurasian avian-like swine influenza A (H1N1) viruses (EAS-H1N1) are predominant in swine and occasionally infect humans. A Eurasian avian-like swine influenza A (H1N1) virus was isolated from a boy who was suffering from fever; this strain was designated A/Shandong-binzhou/01/2021 (H1N1). The aims of this study were to investigate the characteristics of this virus and to draw attention to the need for surveillance of influenza virus infection in swine and humans.MethodsThroat-swab specimens were collected and subjected to real-time fluorescent quantitative polymerase chain reaction (RT‒PCR). Positive clinical specimens were inoculated onto Madin-Darby canine kidney (MDCK) cells to isolate the virus, which was confirmed by a haemagglutination assay. Then, whole-genome sequencing was carried out using an Illumina MiSeq platform, and phylogenetic analysis was performed with MEGA X software.ResultsRT‒PCR revealed that the throat-swab specimens were positive for EAS-H1N1, and the virus was subsequently successfully isolated from MDCK cells; this strain was named A/Shandong-binzhou/01/2021 (H1N1). Whole-genome sequencing and phylogenetic analysis revealed that A/Shandong-binzhou/01/2021 (H1N1) is a novel triple-reassortant EAS-H1N1 lineage that contains gene segments from EAS-H1N1 (HA and NA), triple-reassortant swine influenza H1N2 virus (NS) and A(H1N1) pdm09 viruses (PB2, PB1, PA, NP and MP).ConclusionsThe isolation and analysis of the A/Shandong-binzhou/01/2021 (H1N1) virus provide further evidence that EAS-H1N1 poses a threat to human health, and greater attention should be given to the surveillance of influenza virus infections in swine and humans.

A Comprehensive Review of Our Understanding and Challenges of Viral Vaccines against Swine Pathogens.

Pig farming has become a strategically significant and economically important industry across the globe. It is also a potentially vulnerable sector due to challenges posed by transboundary diseases in which viral infections are at the forefront. Among the porcine viral diseases, African swine fever, classical swine fever, foot and mouth disease, porcine reproductive and respiratory syndrome, pseudorabies, swine influenza, and transmissible gastroenteritis are some of the diseases that cause substantial economic losses in the pig industry. It is a well-established fact that vaccination is undoubtedly the most effective strategy to control viral infections in animals. From the period of Jenner and Pasteur to the recent new-generation technology era, the development of vaccines has contributed significantly to reducing the burden of viral infections on animals and humans. Inactivated and modified live viral vaccines provide partial protection against key pathogens. However, there is a need to improve these vaccines to address emerging infections more comprehensively and ensure their safety. The recent reports on new-generation vaccines against swine viruses like DNA, viral-vector-based replicon, chimeric, peptide, plant-made, virus-like particle, and nanoparticle-based vaccines are very encouraging. The current review gathers comprehensive information on the available vaccines and the future perspectives on porcine viral vaccines.

Applying lessons of COVID-19 and other emerging infectious diseases to future outbreaks.

Infectious diseases are emerging and re-emerging far more frequently than many appreciate. In the past two decades alone, there have been numerous outbreaks (e.g., Ebola, chikungunya, Zika, and Mpox) and pandemics (i.e., swine flu and coronavirus disease 2019) with profound effects to public health, the economy, and society at large. Rather than view these in isolation, there are important lessons pertaining to how best to contend with future outbreaks of emerging infectious diseases. Those lessons span definition (i.e., what constitutes a pandemic), through deficiencies in surveillance, data collection and reporting, the execution of research in a rapidly changing environment, the nuances of study design and hierarchy of clinical evidence, triage according to clinical need as supply chains become overwhelmed, and the challenges surrounding forecasting of outbreaks. Understanding those lessons and drawing on both the successes and failures of the past are imperative if we are to overcome the challenges of outbreak/pandemic responsiveness.

Pulmonary MicroRNA expression after heterologous challenge with swine influenza A virus (H1N2) in immunized and non-immunized pigs

MicroRNAs (miRNAs) contribute to post-transcriptional modulation of the host response during influenza A virus (IAV) infection and may be involved in shaping disease severity. Differential disease severity was achieved in two groups of pigs by immunization of one group with a commercial swine IAV vaccine prior to heterologous IAV (H1N2) challenge of both groups. Lung tissue was harvested 1, 3, and 14 days after challenge and miRNA expression was quantified. Gene Ontology term enrichment analysis was employed to examine the functional relevance of genes potentially regulated by differentially expressed miRNAs in pigs with varying degrees of disease severity following IAV infection. Results suggested that the miRNA response associated with less severe disease may modulate host mechanisms essential for viral life cycle, e.g. transcription, translation, and protein trafficking. During more severe disease, miRNA-mediated regulation may focus on dampening virus-specific processes e.g. virion assembly and viral protein processing, and controlling host metabolism.

Replication kinetics of novel swine influenza A viruses: an approach to vaccine production

Novel swine Influenza A viruses (IAVs) have been described in South America. The objective of this study was to evaluate the replication kinetics of novel swine IAVs as a first step for vaccine production. Different swine IAV lineages (H1N1, H1N2, and H3N2), infection doses (MOI: 1, 0.1, 0.01, 0.001, 0.0001, and 0.00001), harvest times (every 12 h), and substrates (MDCK and Vero cells) were used. For all IAV strains, MDCK cells were the most efficient substrate, generating titers greater than or equal to 128 HAU/50 µL with an MOI of 0.00001 at 60 h post-infection. These data could be useful for vaccine-producing laboratories.

A ferritin nanoparticle vaccine based on the hemagglutinin extracellular domain of swine influenza A (H1N1) virus elicits protective immune responses in mice and pigs.

Swine influenza viruses (SIVs) pose significant economic losses to the pig industry and are a burden on global public health systems. The increasing complexity of the distribution and evolution of different serotypes of influenza strains in swine herds escalates the potential for the emergence of novel pandemic viruses, so it is essential to develop new vaccines based on swine influenza. Here, we constructed a self-assembling ferritin nanoparticle vaccine based on the hemagglutinin (HA) extracellular domain of swine influenza A (H1N1) virus using insect baculovirus expression vector system (IBEVS), and after two immunizations, the immunogenicities and protective efficacies of the HA-Ferritin nanoparticle vaccine against the swine influenza virus H1N1 strain in mice and piglets were evaluated. Our results demonstrated that HA-Ferritin nanoparticle vaccine induced more efficient immunity than traditional swine influenza vaccines. Vaccination with the HA-Ferritin nanoparticle vaccine elicited robust hemagglutinin inhibition titers and antigen-specific IgG antibodies and increased cytokine levels in serum. MF59 adjuvant can significantly promote the humoral immunity of HA-Ferritin nanoparticle vaccine. Furthermore, challenge tests showed that HA-Ferritin nanoparticle vaccine conferred full protection against lethal challenge with H1N1 virus and significantly decreased the severity of virus-associated lung lesions after challenge in both BALB/c mice and piglets. Taken together, these results indicate that the hemagglutinin extracellular-based ferritin nanoparticle vaccine may be a promising vaccine candidate against SIVs infection.

The Performance of Extracorporeal Membrane Oxygenation in Various Viral Pneumonia Pandemics: A Meta-Analysis and Systematic Review

Objective: To compare the effects of extracorporeal membrane oxygenation (ECMO) and routine mechanical ventilation on mortality and the risk of associated adverse events in patients with severe viral pneumonia. Methods: PubMed, the Cochrane Library, Embase, Web of Science, and other databases were searched to collect case-control or cohort studies on prognoses associated with ECMO treatment for viral pneumonia. Search terms included extracorporeal membrane oxygenation, ECMO, viral pneumonia, COVID-19, influenza, MERS, and others. According to the PICOS principle, two evaluators independently screened the literature, extracted the data, cross-checked the data, and extracted the data again. Two researchers evaluated the risk of bias in the included studies according to the Newcastle-Ottawa Scale (NOS) and cross-checked the results. Meta-analysis was performed using RevMan 5.3 software. Results: Nine studies were included for analysis, encompassing a total of 4,330 patients, which were categorized into ECMO and CMV groups. There were no significant differences between the two groups in most baseline data; however, the ECMO group had a lower oxygenation index, and some studies reported higher SOFA scores in the ECMO group compared to the CMV group. There was no significant difference in in-hospital mortality between the two groups. The length of ICU stay, total hospital stay, and total mechanical ventilation time were longer in the ECMO group than in the CMV group. In terms of adverse events, there was no significant difference in the occurrence of kidney injury between the two groups. Bleeding events were reported in two studies, with more bleeding events occurring in the ECMO group. According to the subgroup analysis of different virus types, there were no statistical differences in the above aspects among patients with swine flu, novel coronavirus, and MERS. Conclusion: ECMO has a certain degree of positive significance in the treatment of severe viral pneumonia, but there is no significant difference in the treatment outcome of ECMO across different epidemic periods. The timing of ECMO treatment, patient management, and withdrawal evaluation still need further research.

Pathogenicity and escape to pre-existing immunity of a new genotype of swine influenza H1N2 virus that emerged in France in 2020

In 2020, a new genotype of swine H1N2 influenza virus (H1avN2–HA 1C.2.4) was identified in France. It rapidly spread within the pig population and supplanted the previously predominant H1avN1-HA 1C.2.1 virus. To characterize this new genotype which is genetically and antigenically distant from the other H1avNx viruses detected in France, an experimental study was conducted to compare the outcomes of H1avN2 and H1avN1 infections in pigs and evaluate the protection conferred by the only inactivated vaccine currently licensed in Europe containing an HA 1C (clade 1C.2.2) antigen. Infection with H1avN2 induced stronger clinical signs and earlier shedding than H1avN1. The neutralizing antibodies produced following H1avN2 infection were unable to neutralize H1avN1, and vice versa, whereas the cellular-mediated immunity cross-reacted. Vaccination slightly altered the impact of H1avN2 infection at the clinical level, but did not prevent shedding of infectious virus particles. It induced a cellular-mediated immune response towards H1avN2, but did not produce neutralizing antibodies against this virus. As in vaccinated animals, animals previously infected by H1avN1 developed a cross-reacting cellular immune response but no neutralizing antibodies against H1avN2. However, H1avN1 pre-infection induced a better protection against the H1avN2 infection than vaccination, probably due to higher levels of non-neutralizing antibodies and a mucosal immunity. Altogether, these results showed that the new H1avN2 genotype induced a severe respiratory infection and that the actual vaccine was less effective against this H1avN2-HA 1C.2.4 than against H1avN1-HA 1C.2.1, which may have contributed to the H1avN2 epizootic and dissemination in pig farms in France.

Identification of a New Domestic Pig Cell Line for Growth of African Swine Fever Viruses for Vaccine Production in Uganda.

In this study, a basis for the feasibility of a successful ASF vaccine design program using live attenuated vaccines was sought. One of the challenges to African swine fever (ASF) vaccine development is having a cell line that will provide commercial utility for vaccine production. We set out to address this problem by innovatively identifying possible cell lines from local domestic pigs in the country. Eight tissue types from ASF-negative animals were identified for incorporation into cell line development. These were degraded, incubated, and monitored for cell growth. One cell line, the SIR2-P, grew consistently and confluently and was tested for the ability to grow and isolate field ASF viruses. We report the isolation of ASF viruses in our laboratory for the first time. The P9C virus from Namayingo district exhibited the largest plaque sizes compared to the SQ517B virus from Mukono. The innovative identification of the SIR2-P cell line is proof of concept that newer speciesspecific cell lines can be developed in the Infectious Animal Disease Laboratory (IADL), and utilized to study other animal viruses like Porcine Reproductive and Respiratory Syndrome (PRRS) virus, Foot and mouth disease (FMD) virus, and Swine Influenza. Such cells can be used in vaccine production for other endemic diseases in Uganda. The SIR2-P cell line is currently at passage 65.

UV-Inactivated rVSV-M2e-Based Influenza Vaccine Protected against the H1N1 Influenza Challenge.

To investigate the immune responses and protection ability of ultraviolet light (UV)-inactivated recombinant vesicular stomatitis (rVSV)-based vectors that expressed a fusion protein consisting of four copies of the influenza matrix 2 protein ectodomain (tM2e) and the Dendritic Cell (DC)-targeting domain of the Ebola Glycoprotein (EΔM), (rVSV-EΔM-tM2e). In our previous study, we demonstrated the effectiveness of rVSV-EΔM-tM2e to induce robust immune responses against influenza M2e and protect against lethal challenges from H1N1 and H3N2 strains. Here, we used UV to inactivate rVSV-EΔM-tM2e and tested its immunogenicity and protection in BALB/c mice from a mouse-adapted H1N1 influenza challenge. Using Enzyme-Linked Immunosorbent Assay (ELISA) and Antibody-Dependent Cellular Cytotoxicity (ADCC), the influenza anti-M2e immune responses specific to human, avian and swine influenza strains induced were characterized. Likewise, the specificity of the anti-M2e immune responses induced in recognizing M2e antigen on the surface of the cell was investigated using Fluorescence-Activated Cell Sorting (FACS) analysis. Like the live attenuated rVSV-EΔM-tM2e, the UV-inactivated rVSV-EΔM-tM2e was highly immunogenic against different influenza M2e from strains of different hosts, including human, swine, and avian, and protected against influenza H1N1 challenge in mice. The FACS analysis demonstrated that the induced immune responses can recognize influenza M2 antigens from human, swine and avian influenza strains. Moreover, the rVSV-EΔM-tM2e also induced ADCC activity against influenza M2e from different host strains. These findings suggest that UV-inactivated rVSV-EΔM-tM2e could be used as an inactivated vaccine against influenza viruses.

Influenza surveillance in pigs: balancing act between broad diagnostic coverage and specific virus characterization

BackgroundMonitoring of infectious diseases on swine farms requires a high diagnostic sensitivity and specificity of the test system. Moreover, particularly in cases of swine influenza A virus (swIAV) it is desirable to include characterization of the virus as precisely as possible. This is indispensable for strategies concerning prophylaxis of swIAV and furthermore, to meet the requirements of a purposeful monitoring of newly emerging swIAV strains in terms of vaccine design and public health. Within the present cross-sectional study, we compared the diagnostic value of group samples (wipes of surfaces with direct contact to mouth/nose, dust wipes, udder skin wipes, oral fluids) to individual samples (nasal swabs, tracheobronchial swabs) for both swIAV identification and characterization. Sampling included different stages of pig production on 25 sow farms with attached nursery considered as enzootically infected with swIAV. Firstly, samples were analyzed for IAV genome and subsequently samples with Ct-values < 32 were subtyped by multiplex RT-qPCR.ResultsNasal swabs of suckling piglets and nursery pigs resulted in a higher odds to detect swIAV (p < 0.001) and to identify swIAV subtypes by RT-qPCR (p < 0.05) compared to nasal swabs of sows. In suckling piglets, significant higher rates of swIAV detection could be observed for nasal swabs (p = 0.007) and sow udder skin wipes (p = 0.036) compared to contact wipes. In the nursery, group sampling specimens were significantly more often swIAV positive compared to individual samples (p < 0.01), with exception of the comparison between contact wipes and nasal swabs (p = 0.181). However, in general nasal swabs were more likely to have Ct-value < 32 and thus, to be suitable for subtyping by RT-qPCR compared to dust wipes, contact wipes, udder skin wipes and tracheobronchial swabs (p < 0.05). Interestingly, different subtypes were found in different age groups as well as in different specimens in the same holding.ConclusionAlthough population-based specimens are highly effective for swIAV monitoring, nasal swabs are still the preferable sampling material for the surveillance of on-farm circulating strains due to significantly higher virus loads. Remarkably, sampling strategies should incorporate suckling piglets and different age groups within the nursery to cover as many as possible of the on-farm circulating strains.

MicroRNAs: exploring their role in farm animal disease and mycotoxin challenges.

MicroRNAs (miRNAs) serve as key regulators in gene expression and play a crucial role in immune responses, holding a significant promise for diagnosing and managing diseases in farm animals. This review article summarizes current research on the role of miRNAs in various farm animal diseases and mycotoxicosis, highlighting their potential as biomarkers and using them for mitigation strategies. Through an extensive literature review, we focused on the impact of miRNAs in the pathogenesis of several farm animal diseases, including viral and bacterial infections and mycotoxicosis. They regulate gene expression by inducing mRNA deadenylation, decay, or translational inhibition, significantly impacting cellular processes and protein synthesis. The research revealed specific miRNAs associated with the diseases; for instance, gga-miR-M4 is crucial in Marek's disease, and gga-miR-375 tumor-suppressing function in Avian Leukosis. In swine disease such as Porcine Respiratory and Reproductive Syndrome (PRRS) and swine influenza, miRNAs like miR-155 and miR-21-3p emerged as key regulatory factors. Additionally, our review highlighted the interaction between miRNAs and mycotoxins, suggesting miRNAs can be used as a biomarker for mycotoxin exposure. For example, alterations in miRNA expression, such as the dysregulation observed in response to Aflatoxin B1 (AFB1) in chickens, may indicate potential mechanisms for toxin-induced changes in lipid metabolism leading to liver damage. Our findings highlight miRNAs potential for early disease detection and intervention in farm animal disease management, potentially reducing significant economic losses in agriculture. With only a fraction of miRNAs functionally characterized in farm animals, this review underlines more focused research on specific miRNAs altered in distinct diseases, using advanced technologies like CRISPR-Cas9 screening, single-cell sequencing, and integrated multi-omics approaches. Identifying specific miRNA targets offers a novel pathway for early disease detection and the development of mitigation strategies against mycotoxin exposure in farm animals.

COVAX and COVID‐19 Vaccine Inequity: A case study of G‐20 and African Union

AbstractAs the world has a history of vaccine nationalism, especially during the 2009 Swine flu pandemic, the COVAX alliance, a globally collaborated mechanism, was created by World Health Organization (WHO), GAVI, and UNICEF to address the inequity of COVID‐19 vaccines. One of the primary aims of this alliance was to deliver vaccines to low‐ and middle‐income countries (LMICs), which otherwise have less or no capacity to access vaccines from the open market. It is crucial to explore the contribution of COVAX in bridging the gap in equity, accessibility, and affordability of COVID‐19 vaccines between high‐ and low‐income countries (LICs). We selected Group 20 (G20) COVAX participants and the African Union (AU) as case studies to estimate these gaps. The bilateral purchase data shows that by December 2021, the G20 countries had vaccines more than double their population, whereas the AU could procure only about one fifth (19%) of their population. Out of 52 AU countries whose data was available, only 21 of them could strike a bilateral deal with vaccine manufacturers. Even after COVAX delivery, the share of the population that could be vaccinated in AU was just 36.8%, less than the target of WHO (40%) for December 2021. It was found that the COVAX alliance worked better than the open market competition for LMICs and LICs. The cost of vaccinating 20% of the population was 0.7% of the current health expenditure for G20 countries, whereas AU countries had to spend 5.5%. COVAX bears more cost (1%–3%) for AU countries than G20 countries (less than 1%). COVAX made COVID‐19 vaccines more affordable and accessible to these countries. However, LICs were disproportionately affected even with the COVAX Facility mechanism owing to their lack of vaccine deployment infrastructure.

Mapping the Proposed Caribbean Zoonotic (Swine Influenza) Epidemic of 1493 As a Geographic Model of Infectious Virus Dispersion

This paper investigates the proposed 1493 zoonotic (swine influenza) pandemic that swept through the Spanish colony at La Isabela, Hispaniola. Primary and secondary accounts of the malady describe the attributed symptoms as summarized in the work of Guerra (1988) and attempt to predict the geographic spread of the zoonosis as a series of four expanding regional stages, beginning at La Isabela and nearby Indigenous villages, moving outward along known valley pathways, engulfing northern Hispaniola, and finally transporting the infectious disease to the nearby islands of Cuba, Puerto Rico, Jamaica, and the Bahama Archipelago, with the possibility of spreading to the Lesser Antilles, the eastern coast of Yucatan and Honduras, and the northern coast of South America. This proposed geographic virus dispersion model includes a series of island maps that locate selected archeological sites of known villages along with suggested travel times, providing a historical record of viral spread tracing.