Neu5Gc binding loss of subtype H7 influenza A virus facilitates adaptation to gallinaceous poultry following transmission from waterbirds but restricts spillback.

Migratory waterfowl, gulls, and shorebirds serve as natural reservoirs for influenza A viruses, with potential spillovers to domestic poultry and humans. The intricacies of interspecies adaptation among avian species, particularly from wild birds to domestic poultry, are not fully elucidated. In this study, we investigated the molecular mechanisms underlying avian species barriers in H7 transmission, particularly the factors responsible for the disproportionate distribution of poultry infected with A/Anhui/1/2013 (AH/13)-lineage H7N9 viruses. We hypothesized that the differential expression of N-glycolylneuraminic acid (Neu5Gc) among avian species exerts selective pressure on H7 viruses, shaping their evolution and enabling them to replicate and transmit efficiently among gallinaceous poultry, particularly chickens. Our glycan microarray and biolayer interferometry experiments showed that AH/13-lineage H7N9 viruses exclusively bind to Neu5Ac, in contrast to wild waterbird H7 viruses that bind both Neu5Ac and Neu5Gc. Significantly, reverting the V179 amino acid in AH/13-lineage back to the I179, predominantly found in wild waterbirds, expanded the binding affinity of AH/13-lineage H7 viruses from exclusively Neu5Ac to both Neu5Ac and Neu5Gc. When cultivating H7 viruses in cell lines with varied Neu5Gc levels, we observed that Neu5Gc expression impairs the replication of Neu5Ac-specific H7 viruses and facilitates adaptive mutations. Conversely, Neu5Gc deficiency triggers adaptive changes in H7 viruses capable of binding to both Neu5Ac and Neu5Gc. Additionally, we assessed Neu5Gc expression in the respiratory and gastrointestinal tissues of seven avian species, including chickens, Canada geese, and various dabbling ducks. Neu5Gc was absent in chicken and Canada goose, but its expression varied in the duck species. In summary, our findings reveal the crucial role of Neu5Gc in shaping the host range and interspecies transmission of H7 viruses. This understanding of virus-host interactions is crucial for developing strategies to manage and prevent influenza virus outbreaks in diverse avian populations.

Metagenomics analysis reveals presence of the Merida-like virus in Georgia.

Arbovirus surveillance is fundamental for the discovery of novel viruses and prevention of febrile vector-borne illnesses. Vector-borne pathogens can rapidly expand and adapt in new geographic and environmental conditions. In this study, metagenomic surveillance was conducted to identify novel viruses in the Country of Georgia. A total of 521 mosquitoes were captured near a military training facility and pooled from species Culex pipiens (Linnaeus) (87%) and Aedes albopictus (Skuse) (13%). We decided to further analyze the Culex pipiens mosquitoes, due to the more extensive number of samples collected. Our approach was to utilize an unbiased total RNA-seq for pathogen discovery in order to explore the mosquito virome. The viral reads from this analysis were mostly aligned to Insect-specific viruses from two main families, the Iflaviridae; a positive-stranded RNA virus and the Rhabdoviridae; a negative- and single-stranded RNA virus. Our pathogen discovery analysis revealed viral reads aligning to the Merida-like virus Turkey (MERDLVT) strain among the Rhabdoviridae. To further validate this result, we conducted a BLAST sequence comparison analysis of our samples with the MERDLVT strain. Our positive samples aligned to the MERDLVT strain with 96-100% sequence identity and 99.7-100% sequence coverage. A bootstrapped maximum-likelihood phylogenetic tree was used to evaluate the evolutionary relationships among these positive pooled specimens with the (MERDLVT) strain. The Georgia samples clustered most closely with two strains from Turkey, the Merida-like virus KE-2017a isolate 139-1-21 and the Merida-like virus Turkey isolate P431. Collectively, these results show the presence of the MERDLVT strain in Georgia.

Differential Genome Replication of a Unique Single-Amino-Acid Mutation in the Adenovirus-4 Component of the Live Oral Adenovirus Type 4 and Type 7 Vaccine.

The FDA-approved Adenovirus Type 4 and Type 7 Vaccine, Live, Oral is highly effective and essential in preventing acute respiratory diseases (ARDs) in U.S. military recruits. Our study revealed the presence of a previously undetected mutation, not found in the wild-type human adenovirus type 4 (HAdV-4) component of the licensed vaccine, which contains an amino acid substitution (P388T) in the pre-terminal protein (pTP). This study demonstrated that replication of the T388 HAdV-4 vaccine mutant virus is favored over the wild type in WI-38 cells, the cell type utilized in vaccine manufacturing. However, results from serial human stool specimens of vaccine recipients support differential genome replication in the gastrointestinal tract (GI), demonstrated by the steady decline of the percentage of mutant T388 vaccine virus. Since vaccine efficacy depends upon GI replication and the subsequent immune response, the mutation can potentially impact vaccine efficacy.

A Phase 1 Two-Arm, Randomized, Double-Blind, Active-Controlled Study of Live, Oral Plasmid-Derived Adenovirus Type 4 and Type 7 Vaccines in Seronegative Adults.

PXVX0047 is an investigational vaccine developed for active immunization to prevent febrile acute respiratory disease (ARD) caused by adenovirus serotypes 4 (Ad4) and 7 (Ad7). PXVX0047 consists of a modernized, plasmid-derived vaccine that was generated using a virus isolated from Wyeth Ad4 and Ad7 vaccine tablets. A phase 1 two-arm, randomized, double-blind, active-controlled study was conducted to evaluate the safety profile and immunogenicity of the investigational adenovirus vaccines. The two components of PXVX0047 were administered orally together in a single dose to 11 subjects. For comparison, three additional subjects received the Ad4/Ad7 vaccine that is currently in use by the US military. The results of this study show that the tolerability and immunogenicity of the PXVX0047 Ad7 component are comparable with that of the control Ad4/Ad7 vaccine; however, the immunogenicity of the PXVX0047 Ad4 component was lower than expected. Clinical trial number NCT03160339.

Transmission of SARS-CoV-2 among recruits in a US Army training environment: a brief report.

BACKGROUND: In 2020, preventive measures were implemented to mitigate the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among 600-700 recruits arriving weekly at a basic combat training (BCT) facility in the southern United States. Trainees were sorted into companies and platoons (cocoons) at arrival, tested, quarantined for 14 days with daily temperature and respiratory-symptom monitoring and retested before release into larger groups for training where symptomatic testing was conducted. Nonpharmaceutical measures, such as masking, and social distancing, were maintained throughout quarantine and BCT. We assessed for SARS-CoV-2 transmission in the quarantine milieu. METHODS: Nasopharyngeal (NP) swabs were collected at arrival and at the end of quarantine and blood specimens at both timepoints and at the end of BCT. Epidemiological characteristics were analyzed for transmission clusters identified from whole-genome sequencing of NP samples. RESULTS: Among 1403 trainees enrolled from 25 August to 7 October 2020, epidemiological analysis identified three transmission clusters (n = 20 SARS-CoV-2 genomes) during quarantine, which spanned five different cocoons. However, SARS-CoV-2 incidence decreased from 2.7% during quarantine to 1.5% at the end of BCT; prevalence at arrival was 3.3%. CONCLUSIONS: These findings suggest layered SARS-CoV-2 mitigation measures implemented during quarantine minimized the risk of further transmission in BCT.

Successful treatment of a blunt retrohepatic vena cava injury using an atriocaval shunt without sternotomy or thoracotomy: a case report.

Retrohepatic vena cava (RHIVC) injury is often fatal and can be very difficult to manage. Total hepatic vascular isolation, a shunt, or bypass surgery is required for the surgical treatment of RHIVC injury in hemodynamically unstable patients; however, these are not easy procedures. Here, we present a case of RHIVC injury that was successfully treated by atriocaval shunt placement via a transdiaphragmatic incision without sternotomy or thoracotomy. In addition, we review the resuscitation and surgical procedures used for total hepatic vascular isolation in patients with RHIVC injury.

SARS-CoV-2 Exposure in Norway Rats (Rattus norvegicus) from New York City.

Millions of Norway rats (Rattus norvegicus) inhabit New York City (NYC), presenting the potential for transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from humans to rats. We evaluated SARS-CoV-2 exposure among 79 rats captured from NYC during the fall of 2021. Our results showed that 13 of the 79 rats (16.5%) tested IgG- or IgM-positive, and partial SARS-CoV-2 genomes were recovered from all 4 rats that were qRT-PCR (reverse transcription-quantitative PCR)-positive. Genomic analyses suggest these viruses were associated with genetic lineage B, which was predominant in NYC in the spring of 2020 during the early pandemic period. To further investigate rat susceptibility to SARS-CoV-2 variants, we conducted a virus challenge study and showed that Alpha, Delta, and Omicron variants can cause infections in wild-type Sprague Dawley (SD) rats, including high replication levels in the upper and lower respiratory tracts and induction of both innate and adaptive immune responses. Additionally, the Delta variant resulted in the highest infectivity. In summary, our results indicate that rats are susceptible to infection with Alpha, Delta, and Omicron variants, and wild Norway rats in the NYC municipal sewer systems have been exposed to SARS-CoV-2. Our findings highlight the need for further monitoring of SARS-CoV-2 in urban rat populations and for evaluating the potential risk of secondary zoonotic transmission from these rat populations back to humans. IMPORTANCE The host tropism expansion of SARS-CoV-2 raises concern for the potential risk of reverse-zoonotic transmission of emerging variants into rodent species, including wild rat species. In this study, we present both genetic and serological evidence for SARS-CoV-2 exposure to the New York City wild rat population, and these viruses may be linked to the viruses that were circulating during the early stages of the pandemic. We also demonstrated that rats are susceptible to additional variants (i.e., Alpha, Delta, and Omicron) that have been predominant in humans and that susceptibility to infection varies by variant. Our findings highlight the reverse zoonosis of SARS-CoV-2 to urban rats and the need for further monitoring of SARS-CoV-2 in rat populations for potential secondary zoonotic transmission to humans.

Clustered cases of human adenovirus types 4, 7, and 14 infections in US Department of Defense Beneficiaries during the 2018-2019 season.

Human adenoviruses (HAdV) are genetically diverse and can infect a number of tissues with severities varied from mild to fatal. HAdV types 3, 4, 7, 11, 14, 21, and 55 were associated with acute respiratory illnesses outbreaks in the United States and in other countries. The risk of outbreaks can be effectively controlled by HAdV vaccination or mitigated by screening and preventive measures. During the influenza season 2018-2019, the DoD Global Respiratory Pathogen Surveillance Program (DoDGRS) received 24 300 respiratory specimens. HAdV samples that produced positive cytopathic effects in viral cultivation were subjected to next-generation sequencing for genome sequence assembly, genome typing, whole genome phylogeny, and sequence comparative analyses. A variety of HAdV types were identified in this study, including HAdV types 1-7, 14, 55, and 56. HAdV types 4, 7, and 14 were found in clustered cases in Colorado, Florida, New York, and South Carolina. Comparative sequence analyses of these isolates revealed the emergence of novel genetic mutations despite the stability of adenovirus genomes. Genomic surveillance of HAdV suggested possible undetected outbreaks and shed light on prevalence, genetic divergence, and viral evolution of HAdV. Continued surveillance will inform risk assessment and countermeasures.

Application of multi-SVM classifier and hybrid GSAPSO algorithm for fault diagnosis of electrical machine drive system.

A method, being based on multi-class support vector machine (SVM) classifier and hybrid particle swarm optimization (PSO) and gravity search algorithm (GSA), is presented to diagnose the faults in electrical motor drive system. In this method, the global search ability of PSO and the local search ability of GSA are integrated to combine the advantages of PSO and GSA, and the multi-class SVM classifier is optimized by the hybrid GSAPSO algorithm to improve classification performance. To test the presented method, a series of simulation and experiment are studied. The diagnostic results display that the presented method can gain more precise classification accuracy than multi-class SVM with PSO and multi-class SVM with GSA.

Rural populations facilitated early SARS-CoV-2 evolution and transmission in Missouri, USA.

In the United States, rural populations comprise 60 million individuals and suffered from high COVID-19 disease burdens. Despite this, surveillance efforts are biased toward urban centers. Consequently, how rurally circulating SARS-CoV-2 viruses contribute toward emerging variants remains poorly understood. In this study, we aim to investigate the role of rural communities in the evolution and transmission of SARS-CoV-2 during the early pandemic. We collected 544 urban and 435 rural COVID-19-positive respiratory specimens from an overall vaccine-naïve population in Southwest Missouri between July and December 2020. Genomic analyses revealed 53 SARS-CoV-2 Pango lineages in our study samples, with 14 of these lineages identified only in rural samples. Phylodynamic analyses showed that frequent bi-directional diffusions occurred between rural and urban communities in Southwest Missouri, and that four out of seven Missouri rural-origin lineages spread globally. Further analyses revealed that the nucleocapsid protein (N):R203K/G204R paired substitutions, which were detected disproportionately across multiple Pango lineages, were more associated with urban than rural sequences. Positive selection was detected at N:204 among rural samples but was not evident in urban samples, suggesting that viruses may encounter distinct selection pressures in rural versus urban communities. This study demonstrates that rural communities may be a crucial source of SARS-CoV-2 evolution and transmission, highlighting the need to expand surveillance and resources to rural populations for COVID-19 mitigation.

SARS-CoV-2 exposure in Norway rats (Rattus norvegicus) from New York City.

Millions of Norway rats (Rattus norvegicus) inhabit New York City (NYC), presenting the potential for transmission of SARS-CoV-2 from humans to rats and other wildlife. We evaluated SARS-CoV-2 exposure among 79 rats captured from NYC during the fall of 2021. Results showed that 13 of 79 rats (16.5%) tested IgG or IgM positive, and partial genomes of SARS-CoV-2 were recovered from four rats that were qRT-PCR positive. Using a virus challenge study, we also showed that Alpha, Delta, and Omicron variants can cause robust infections in wild-type Sprague Dawley (SD) rats, including high level replications in the upper and lower respiratory tracts and induction of both innate and adaptive immune responses. Additionally, the Delta variant resulted in the highest infectivity. In summary, our results indicated that rats are susceptible to infection with Alpha, Delta, and Omicron variants, and rats in the NYC municipal sewer systems have been exposed to SARS-CoV-2. Our findings highlight the potential risk of secondary zoonotic transmission from urban rats and the need for further monitoring of SARS-CoV-2 in those populations.

SARS-CoV-2 and influenza co-infection: A cross-sectional study in central Missouri during the 2021-2022 influenza season.

As SARS-CoV-2 and influenza viruses co-circulate, co-infections with these viruses generate an increasing concern to public health. To evaluate the prevalence and clinical impacts of SARS-CoV-2 and influenza A virus co-infections during the 2021-2022 influenza season, SARS-CoV-2-positive samples from 462 individuals were collected from October 2021 to January 2022. Of these individuals, 152 tested positive for influenza, and the monthly co-infection rate ranged from 7.1% to 48%. Compared to the Delta variant, individuals infected with Omicron were less likely to be co-infected and hospitalized, and individuals who received influenza vaccines were less likely to become co-infected. Three individuals had two samples collected on different dates, and all three developed a co-infection after their initial SARS-CoV-2 infection. This study demonstrates high prevalence of co-infections in central Missouri during the 2021-2022 influenza season, differences in co-infection prevalence between the Delta and the Omicron waves, and the importance of influenza vaccinations against co-infections.

Discovery of Rickettsia spp. in mosquitoes collected in Georgia by metagenomics analysis and molecular characterization.

Arthropods have a broad and expanding worldwide presence and can transmit a variety of viral, bacterial, and parasite pathogens. A number of Rickettsia and Orientia species associated with ticks, fleas, lice, and mites have been detected in, or isolated from, patients with febrile illness and/or animal reservoirs throughout the world. Mosquitoes are not currently considered vectors for Rickettsia spp. pathogens to humans or to animals. In this study, we conducted a random metagenome next-generation sequencing (NGS) of 475 pools of Aedes, Culex, and Culiseta species of mosquitoes collected in Georgia from 2018 to 2019, identifying rickettsial gene sequences in 33 pools of mosquitoes. We further confirmed the findings of the Rickettsia by genus-specific quantitative PCR (qPCR) and multi-locus sequence typing (MLST). The NGS and MLST results indicate that Rickettsia spp. are closely related to Rickettsia bellii, which is not known to be pathogenic in humans. The results, together with other reports of Rickettsia spp. in mosquitoes and the susceptibility and transmissibility experiments, suggest that mosquitoes may play a role in the transmission cycle of Rickettsia spp.

Interval-valued intuitionistic fuzzy multi-attribute group decision-making method considering risk preference of decision-makers and its application.

An improved interval-valued intuitionistic fuzzy multi-attribute group decision-making method considering the risk preference of decision-makers is proposed to solve the multi-attribute group decision-making problem with interval-valued intuitionistic fuzzy numbers and the condition that the attribute weight information is completely unknown. Firstly, the decision-maker weight of each attribute is determined by combining similarity and proximity. In order to consider the influence of the decision-maker's risk preference on the decision result and avoid the asymptotic behavior of interval-valued intuitionistic fuzzy matrix, the risk aversion coefficient of the decision-maker is introduced and combined with the determined decision-maker's weight aggregation to form a group decision matrix. Then, the information of group decision matrix is mined, and the interval-valued intuitionistic fuzzy entropy is used to determine the attribute weight and relative weight. Based on the interval-valued intuitionistic fuzzy distance measure formula and the TODIM method, the overall superiority of each scheme relative to other schemes is obtained by calculating the superiority between schemes, and the optimal scheme is determined by comparing and sequencing. Finally, the rationality and effectiveness of the proposed method are verified by an example of mechanical assembly supplier selection decision.

Genomic surveillance of SARS-CoV-2 in US military compounds in Afghanistan reveals multiple introductions and outbreaks of Alpha and Delta variants.

BACKGROUND: With the emergence and spread of SARS-CoV-2 variants, genomic epidemiology and surveillance have proven invaluable tools for variant tracking. Here, we analyzed SARS-CoV-2 samples collected from personnel located at the US/NATO bases across Afghanistan. RESULTS: Sequencing and phylogenetic analyses revealed at least 16 independent introductions of SARS-CoV-2 into four of these relatively isolated compounds during April and May 2021, including multiple introductions of Alpha and Delta variants. Four of the introductions resulted in sustained spread of the virus within, and in two cases between, the compounds. Three of these outbreaks, one Delta and two Alpha, occurred simultaneously. CONCLUSIONS: Even in rigorously controlled and segregated environments, SARS-CoV-2 introduction and spread may occur frequently.

Phase separation of insulin receptor substrate 1 drives the formation of insulin/IGF-1 signalosomes.

As a critical node for insulin/IGF signaling, insulin receptor substrate 1 (IRS-1) is essential for metabolic regulation. A long and unstructured C-terminal region of IRS-1 recruits downstream effectors for promoting insulin/IGF signals. However, the underlying molecular basis for this remains elusive. Here, we found that the C-terminus of IRS-1 undergoes liquid-liquid phase separation (LLPS). Both electrostatic and hydrophobic interactions were seen to drive IRS-1 LLPS. Self-association of IRS-1, which was mainly mediated by the 301-600 region, drives IRS-1 LLPS to form insulin/IGF-1 signalosomes. Moreover, tyrosine residues of YXXM motifs, which recruit downstream effectors, also contributed to IRS-1 self-association and LLPS. Impairment of IRS-1 LLPS attenuated its positive effects on insulin/IGF-1 signaling. The metabolic disease-associated G972R mutation impaired the self-association and LLPS of IRS-1. Our findings delineate a mechanism in which LLPS of IRS-1-mediated signalosomes serves as an organizing center for insulin/IGF-1 signaling and implicate the role of aberrant IRS-1 LLPS in metabolic diseases.

Contingency response decision of network public opinion emergencies based on intuitionistic fuzzy entropy and preference information of decision makers.

A multi-attribute group decision-making (MAGDM) method based on intuitionistic fuzzy preference information is proposed for the multi-attribute intuitionistic fuzzy group decision-making problem where the decision-makers weight and attribute weight are completely unknown and the decision-maker has preference information for the scheme. Firstly, an intuitionistic fuzzy interval judgment matrix is established to describe the original data of the key decision indicators for multiple network public opinion emergencies that erupt simultaneously. Secondly, the attribute weights are determined based on the improved intuitionistic fuzzy entropy construction method, and the expert weights are determined by using objective decision information, taking into account the intuitionistic fuzzy entropy of decision matrix. MAGDM can not only synthesize experts' professional experience in different aspects, but also avoid experts' decision-making errors caused by insufficient domain knowledge. It is necessary to continuously adjust the expert weight based on decision-making information to make the comprehensive decision-making information more accurate. Thirdly, a scheme preference model and an attribute weight optimization model are established to determine the ranking method of intuitionistic fuzzy interval values. Then, a modified distance measure of intuitionistic fuzzy sets (IFSs) is introduced to make the evaluation result more accurate and reasonable when it comes to solving the deviation between the evaluation value and ideal solution of each scheme. Finally, the effectiveness and practicability of the proposed decision-making method are verified by an example of emergency crisis severity, It assists decision makers in selecting and implementing the optimal emergency response plan in a timely and efficient manner, which improves the emergency treatment efficiency of network public opinion crisis, helps emergency departments to better deal with the network public opinion crisis, improves the ability of public opinion guidance and control, and provides a new method and idea for multi-attribute intuitionistic fuzzy group decision-making problem.

Infectious Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in Exhaled Aerosols and Efficacy of Masks During Early Mild Infection.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) epidemiology implicates airborne transmission; aerosol infectiousness and impacts of masks and variants on aerosol shedding are not well understood. METHODS: We recruited coronavirus disease 2019 (COVID-19) cases to give blood, saliva, mid-turbinate and fomite (phone) swabs, and 30-minute breath samples while vocalizing into a Gesundheit-II, with and without masks at up to 2 visits 2 days apart. We quantified and sequenced viral RNA, cultured virus, and assayed serum samples for anti-spike and anti-receptor binding domain antibodies. RESULTS: We enrolled 49 seronegative cases (mean days post onset 3.8 ±â€…2.1), May 2020 through April 2021. We detected SARS-CoV-2 RNA in 36% of fine (≤5 µm), 26% of coarse (>5 µm) aerosols, and 52% of fomite samples overall and in all samples from 4 alpha variant cases. Masks reduced viral RNA by 48% (95% confidence interval [CI], 3 to 72%) in fine and by 77% (95% CI, 51 to 89%) in coarse aerosols; cloth and surgical masks were not significantly different. The alpha variant was associated with a 43-fold (95% CI, 6.6- to 280-fold) increase in fine aerosol viral RNA, compared with earlier viruses, that remained a significant 18-fold (95% CI, 3.4- to 92-fold) increase adjusting for viral RNA in saliva, swabs, and other potential confounders. Two fine aerosol samples, collected while participants wore masks, were culture-positive. CONCLUSIONS: SARS-CoV-2 is evolving toward more efficient aerosol generation and loose-fitting masks provide significant but only modest source control. Therefore, until vaccination rates are very high, continued layered controls and tight-fitting masks and respirators will be necessary.

Investigation of an outbreak of COVID-19 among U.S. military personnel and beneficiaries stationed in the Republic of Korea, June-July 2021.

On 28 May 2021, leisure travel restrictions in place to control coronavirus disease 2019 (COVID-19) were eased among vaccinated U.S. military personnel and beneficiaries stationed in South Korea (USFK) allowing access to bars and clubs which were off limits. We describe results from an investigation of the largest severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak as of November 2021 among USFK personnel following this change in policy. Data such as SARS-CoV-2 real-time polymerase chain reaction (RT-PCR) test results, demographic characteristics, symptom and vaccination histories, and genome sequences were analyzed. Of a total 207 new cases of COVID-19 diagnosed among USFK members from 15 June to 27 July 2021, 113 (57%) eligible cases were fully vaccinated, of whom 86 (76%) were symptomatic. RT-PCR cycling threshold values were similar among vaccinated and unvaccinated members. Whole genomic sequencing of 54 outbreak samples indicated all infections were due to the Delta variant. Phylogenetic analysis revealed two sources of SARS-CoV-2 accounted for 41% of infections among vaccinated and unvaccinated members. Vaccinated personnel were not at risk of severe illness; however, 86% experienced symptoms following infection. There were no hospitalizations among COVID-19 cases, most of whom were young military service members. Rescinded restrictions were reinstated to control the outbreak. Masking was mandated among all personnel predating U.S. national recommendations for indoor masking in high COVID-19 transmission areas. Increased vaccination with continued vigilance and extension of COVID-19 mitigation measures are warranted to contain the spread of SARS-CoV-2 variants of concern.

Collaborative Learning of Label Semantics and Deep Label-Specific Features for Multi-Label Classification.

In multi-label classification, the strategy of label-specific features has been shown to be effective to learn from multi-label examples by accounting for the distinct discriminative properties of each class label. However, most existing approaches exploit the semantic relations among labels as immutable prior knowledge, which may not be appropriate to constrain the learning process of label-specific features. In this paper, we propose to learn label semantics and label-specific features in a collaborative way. Accordingly, a deep neural network (DNN) based approach named CLIF, i.e. Collaborative Learning of label semantIcs and deep label-specific Features for multi-label classification, is proposed. By integrating a graph autoencoder for encoding semantic relations in the label space and a tailored feature-disentangling module for extracting label-specific features, CLIF is able to employ the learned label semantics to guide mining label-specific features and propagate label-specific discriminative properties to the learning process of the label semantics. In such a way, the learning of label semantics and label-specific features interact and facilitate with each other so that label semantics can provide more accurate guidance to label-specific feature learning. Comprehensive experiments on 14 benchmark data sets show that our approach outperforms other well-established multi-label classification algorithms.