Molecular characterization of emerging recombinant African swine fever virus of genotype I and II in Vietnam, 2023.

African swine fever virus (ASFV) recombinant strains pose new challenges for diagnosis and control. This study characterizes genotype I and II recombinant ASFV strains identified in northern Vietnam in 2023 through whole-genome sequencing and comparative genomic analysis. Seven ASFV-positive samples from six provinces were analyzed, with recombinant strains detected in Bac Giang, Phu Tho, and Vinh Phuc provinces.

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.

H1N1 nanobody development and therapeutic efficacy verification in H1N1-challenged mice.

Influenza A virus causes numerous deaths and infections worldwide annually. Therefore, we have considered nanobodies as a potential treatment for patients with severe cases of influenza. We developed a nanobody that was expected to have protective efficacy against the A/California/04/2009 (CA/04; pandemic 2009 flu strain) and evaluated its therapeutic efficacy against CA/04 in mice experiments.

Immune Cells Are Differentially Affected by SARS-CoV-2 Viral Loads in K18-hACE2 Mice.

Viral load and the duration of viral shedding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are important determinants of the transmission of coronavirus disease 2019. In this study, we examined the effects of viral doses on the lung and spleen of K18-hACE2 transgenic mice by temporal histological and transcriptional analyses. Approximately, 1×10 plaque-forming units (PFU) of SARS-CoV-2 induced strong host responses in the lungs from 2 days post inoculation (dpi) which did not recover until the mice died, whereas responses to the virus were obvious at 5 days, recovering to the basal state by 14 dpi at 1×10 PFU.

Detection of Recombinant African Swine Fever Virus Strains of p72 Genotypes I and II in Domestic Pigs, Vietnam, 2023.

African swine fever virus (ASFV) genotype II is endemic to Vietnam. We detected recombinant ASFV genotypes I and II (rASFV I/II) strains in domestic pigs from 6 northern provinces in Vietnam. The introduction of rASFV I/II strains could complicate ongoing ASFV control measures in the region.

Assessment of the immune interference effects of multivalent vaccine for influenza epidemic strain in 2022-2023 and evaluation of its efficacy.

The various strains of influenza virus cause respiratory symptoms in humans every year and annual vaccinations are recommended. Due to its RNA-type genes and segmented state, it belongs to a virus that mutates frequently with antigenic drift and shift, giving rise to various strains. Each year, the World Health Organization identifies the epidemic strains and operates a global surveillance system to suggest the viral composition for the influenza vaccine.

Genetic characterization and pathogenicity in a mouse model of newly isolated bat-originated mammalian orthoreovirus in South Korea.

Mammalian orthoreoviruses (MRVs) infect a wide range of hosts, including humans, livestock, and wildlife. In the present study, we isolated a novel from the intestine of a microbat () and investigated its biological and pathological characteristics. Phylogenetic analysis indicated that the new isolate was serotype 2, sharing the segments with those from different hosts.

Self-Assembled Nanostructures Presenting Repetitive Arrays of Subunit Antigens for Enhanced Immune Response.

Infectious diseases pose persistent threats to public health, demanding advanced vaccine technologies. Nanomaterial-based delivery systems offer promising solutions to enhance immunogenicity while minimizing reactogenicity. We introduce a self-assembled vaccine (SAV) platform employing antigen-polymer conjugates designed to facilitate robust immune responses.

Development of a neutralization monoclonal antibody with a broad neutralizing effect against SARS-CoV-2 variants.

Background: The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants has challenged the effectiveness of current therapeutic regimens. Here, we aimed to develop a potent SARS-CoV-2 antibody with broad neutralizing effect by screening a scFv library with the spike protein receptor-binding domain (RBD) via phage display.

Methods: SKAI-DS84 was identified through phage display, and we performed pseudovirus neutralization assays, authentic virus neutralization assays, and in vivo neutralization efficacy evaluations.

Advanced Strategies for Developing Vaccines and Diagnostic Tools for African Swine Fever.

African swine fever (ASF) is one of the most lethal infectious diseases affecting domestic pigs and wild boars of all ages. Over a span of 100 years, ASF has continued to spread over continents and adversely affects the global pig industry. To date, no vaccine or treatment has been approved.

Lessons for cross-species viral transmission surveillance from highly pathogenic avian influenza Korean cat shelter outbreaks.

Recent highly pathogenic avian influenza A(H5N1) outbreaks in two Korean cat shelters highlight the need to enhance surveillance for cross-species viral transmission into animal populations kept by humans for non-agricultural or non-conventional livestock farming purposes from a One Health perspective.

A Whole-Genome Analysis of the African Swine Fever Virus That Circulated during the First Outbreak in Vietnam in 2019 and Subsequently in 2022.

Since its initial report in Vietnam in early 2019, the African swine fever (ASF), a highly lethal and severe viral swine disease worldwide, continues to cause outbreaks in other Southeast Asian countries. This study analyzed and compared the genomic sequences of ASF viruses (ASFVs) during the first outbreak in Hung Yen (VN/HY/2019-ASFV1) and Quynh Phu provinces (VN/QP/2019-ASFV1) in Vietnam in 2019, and the subsequent outbreak in Hung Yen (VN/HY/2022-ASFV2) in 2022, to those of other ASFV strains. VN/HY/2019-ASFV1, VN/QP/2019-ASFV1, and VN/HY/2022-ASFV2 genomes were 189,113, 189,081, and 189,607 bp in length, encoding 196, 196, and 203 open reading frames (ORFs), respectively.

Mucosal and cellular immune responses elicited by nasal and intramuscular inoculation with ASFV candidate immunogens.

African swine fever (ASF) is an infectious disease caused by African swine fever virus (ASFV) that is highly contagious and has an extremely high mortality rate (infected by virulent strains) among domestic and wild pigs, causing huge economic losses to the pig industry globally. In this study, SDS-PAGE gel bands hybridized with ASFV whole virus protein combined with ASFV-convalescent and ASFV-positive pig serum were identified by mass spectrometry. Six antigens were detected by positive serum reaction bands, and eight antigens were detected in ASFV-convalescent serum.

Human-to-Animal Transmission of SARS-CoV-2, South Korea, 2021.

To investigate SARS-CoV-2 transmission from humans to animals in Seoul, South Korea, we submitted samples from companion animals owned by persons with confirmed COVID-19. Real-time PCR indicated higher SARS-CoV-2 viral infection rates for dogs and cats than previously reported from the United States and Europe. Host-specific adaptations could introduce mutant SARS-CoV-2 to humans.

Rapid Visible Detection of African Swine Fever Virus Using Hybridization Chain Reaction-Sensitized Magnetic Nanoclusters and Affinity Chromatography.

African swine fever virus (ASFV) is a severe and persistent threat to the global swine industry. As there are no vaccines against ASFV, there is an immense need to develop easy-to-use, cost-effective, and rapid point-of-care (POC) diagnostic platforms to detect and prevent ASFV outbreaks. Here, a novel POC diagnostic system based on affinity column chromatography for the optical detection of ASFV is presented.

Experimental Infection and Transmission of SARS-CoV-2 Delta and Omicron Variants among Beagle Dogs.

We assessed susceptibility of dogs to SARS-COV-2 Delta and Omicron variants by experimentally inoculating beagle dogs. Moreover, we investigated transmissibility of the variants from infected to naive dogs. The dogs were susceptible to infection without clinical signs and transmitted both strains to other dogs through direct contact.

Susceptibility to SARS-CoV-2 and MERS-CoV in Beagle Dogs.

The coronavirus disease 19 (COVID-19) pandemic, caused by the severe acute respiratory syndrome, coronavirus 2 (SARS-CoV-2), has resulted in unprecedented challenges to healthcare worldwide. In particular, the anthroponotic transmission of human coronaviruses has become a common concern among pet owners. Here, we experimentally inoculated beagle dogs with SARS-CoV-2 or Middle East respiratory syndrome (MERS-CoV) to compare their susceptibility to and the pathogenicity of these viruses.

Evaluation of a biotin-based surrogate virus neutralization test for detecting postvaccination antibodies against SARS-CoV-2 variants in sera.

A severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) surrogate virus neutralization test (sVNT) was used to determine the degree of inhibition of binding between human angiotensin converting enzyme 2 (hACE2) and the receptor binding domain (RBD) of spike protein by neutralizing antibodies in a biosafety level 2 facility. Here, to improve the sensitivity and specificity of the commercial sVNT, we developed a new biotin based sVNT using biotinylated RBD and HRP conjugated streptavidin instead of HRP conjugated RBD for direct detection in an ELISA assay that strongly correlated to the FDA approved cPass sVNT commercial kit (R = 0.8521) and pseudo virus neutralization test (R = 0.

Establishment of multicenter COVID-19 therapeutics preclinical test system in Republic of Korea.

Throughout the recent COVID-19 pandemic, South Korea led national efforts to develop vaccines and therapeutics for SARS-CoV-2. The project proceeded as follows: 1) evaluation system setup (including Animal Biosafety Level 3 (ABSL3) facility alliance, standardized nonclinical evaluation protocol, and laboratory information management system), 2) application (including committee review and selection), and 3) evaluation (including expert judgment and reporting). After receiving 101 applications, the selection committee reviewed pharmacokinetics, toxicity, and efficacy data and selected 32 final candidates.

Magnetic-bead-based DNA-capture-assisted real-time polymerase chain reaction and recombinase polymerase amplification for the detection of African swine fever virus.

African swine fever (ASF) is a deadly disease in swine caused by African swine fever virus (ASFV). The global spread of ASFV has resulted in significant economic losses worldwide. Improved early detection has been the most important first line of defense for preventing ASF outbreaks and for activating control measures.