Age-related rhesus macaque models of COVID-19

Background:Since December 2019,an outbreak of the Corona Virus disease 2019(COVID-19)caused by severe acute respiratory syndrome coronavirus(SARS-CoV-2)in Wuhan,China,has become a public health emergency of international concern.The high fatality of aged cases caused by SARS-CoV-2 was a need to explore the possible age-related phenomena with non-human primate models.Methods:Three 3-5 years old and two 15 years old rhesus macaques were intratracheally infected with SARS-CoV-2,and then analyzed by clinical signs,viral replication,chest X-ray,histopathological changes and immune response.Results:Viral replication of nasopharyngeal swabs,anal swabs and lung in old monkeys was more active than that in young monkeys for 14 days after SARS-CoV-2 challenge.Monkeys developed typical interstitial pneumonia characterized by thickened alveolar septum accompanied with inflammation and edema,notably,old monkeys exhibited diffuse severe interstitial pneumonia.Viral antigens were detected mainly in alveolar epithelial cells and macrophages.Conclusion:SARS-CoV-2 caused more severe interstitial pneumonia in old monkeys than that in young monkeys.Rhesus macaque models infected with SARS-CoV-2 provided insight into the pathogenic mechanism and facilitated the development of vaccines and therapeutics against SARS-CoV-2 infection.

Development of two multiplex real-time PCR assays for simultaneous detection and differentiation of monkeypox virus IIa,IIb,and I clades and the B.1 lineage

An ongoing multi-country outbreak of monkeypox was reported in May 2022 with several deaths,affecting 107 countries of all six World Health Organization(WHO)regions.The WHO has declared the current monkeypox outbreak to be a Public Health Emergency of International Concern.It is,thus,necessary to rapidly and accurately detect and distinguish different monkeypox virus(MPXV)clades.We designed primers and probes based on the alignment of 138 complete genomes of poxviruses.In Panel 1,we mixed one pair of primers and three probes to detect and differentiate the MPXV Western Africa(IIa,IIb clade)and Congo Basin(I clade)and other orthopoxviruses.In Panel 2,we mixed one pair of primers and two probes to detect the 2022 MPXV(B.1 lineage and its descendant lineages).In addition,we tested the specificity and sensitivity of the assay using real-time PCR.In Panel 1,the assay reproducibly identified various concentrations of two plasmids of the monkeypox virus,whereas other orthopoxviruses did not cross-react.In Panel 2,the probe annealed well to MPXV B.1 and showed the expected linearity.These two multiple real-time assays are inclusive and highly specific for identifying different clades of MPXV.

Improving Cross-Protection against Influenza Virus Using Recombinant Vaccinia Vaccine Expressing NP and M2 Ectodomain Tandem Repeats

Conventional influenza vaccines need to be designed and manufactured yearly.However,they occasionally provide poor protection owing to antigenic mismatch.Hence,there is an urgent need to develop universal vaccines against influenza virus.Using nucleoprotein(NP)and extracellular domain of matrix protein 2(M2e)genes from the influenza A virus A/Beijing/30/95(H3N2),we constructed four recombinant vaccinia virus-based influenza vaccines carrying NP fused with one or four copies of M2e genes in different orders.The recombinant vaccinia viruses were used to immunize BALB/C mice.Humoral and cellular responses were measured,and then the immunized mice were challenged with the influenza A virus A/Puerto Rico/8/34(PR8).NP-specific humoral response was elicited in mice immunized with recombinant vaccinia viruses carrying full-length NP,while robust M2e-specific humoral response was elicited only in the mice immunized with recombinant vaccinia viruses carrying multiple copies of M2e.All recombinant viruses elicited NP-and M2e-specific cellular immune responses in mice.Only immunization with RVJ-4M2eNP induced remarkably higher levels of IL-2 and IL-10 cytokines specific to M2e.Furthermore,RVJ-4M2eNP immunization provided the highest cross-protection in mice challenged with 20 MLD5〇of PR8.Therefore,the cross-protection potentially correlates with both NP and M2e-specific humoral and cellular immune responses induced by RVJ-4M2eNP,which expresses a fusion antigen of full-length NP preceded by four M2e repeats.These results suggest that the rational fusion of NP and multiple M2e antigens is critical toward inducing protective immune responses,and the 4M2eNP fusion antigen may be employed to develop a universal influenza vaccine.

Description of the First Strain of 2019-nCoV,C-Tan-nCoV Wuhan Strain-National Pathogen Resource Center,China,2020

The recent outbreak of novel coronavirus-infected pneumonia(NCIP)in China(1)has attracted much attention domestically and internationally.As the outbreak occurred,China carried out emergency responses quickly,notified the World Health Organization(WHO)in a timely manner,and shared the viral gene sequence with international communities immediately after pathogenic identification.

Mpox(formerly monkeypox):pathogenesis,prevention,and treatment

In 2022,a global outbreak of Mpox(formerly monkeypox)occurred in various countries across Europe and America and rapidly spread to more than 100 countries and regions.The World Health Organization declared the outbreak to be a public health emergency of international concern due to the rapid spread of the Mpox virus.Consequently,nations intensified their efforts to explore treatment strategies aimed at combating the infection and its dissemination.Nevertheless,the available therapeutic options for Mpox virus infection remain limited.So far,only a few numbers of antiviral compounds have been approved by regulatory authorities.Given the high mutability of the Mpox virus,certain mutant strains have shown resistance to existing pharmaceutical interventions.This highlights the urgent need to develop novel antiviral drugs that can combat both drug resistance and the potential threat of bioterrorism.Currently,there is a lack of comprehensive literature on the pathophysiology and treatment of Mpox.To address this issue,we conducted a review covering the physiological and pathological processes of Mpox infection,summarizing the latest progress of anti-Mpox drugs.Our analysis encompasses approved drugs currently employed in clinical settings,as well as newly identified small-molecule compounds and antibody drugs displaying potential antiviral efficacy against Mpox.Furthermore,we have gained valuable insights from the process of Mpox drug development,including strategies for repurposing drugs,the discovery of drug targets driven by artificial intelligence,and preclinical drug development.The purpose of this review is to provide readers with a comprehensive overview of the current knowledge on Mpox.

Rapid identification of full-length genome and tracing variations of monkeypox virus in clinical specimens based on mNGS and amplicon sequencing

The monkeypox virus(MPXV)has triggered a current outbreak globally.Genome sequencing of MPXV and rapid tracing of genetic variants will benefit disease diagnosis and control.It is a significant challenge but necessary to optimize the strategy and application of rapid full-length genome identification and to track variations of MPXV in clinical specimens with low viral loads,as it is one of the DNA viruses with the largest genome and the most AT-biased,and has a significant number of tandem repeats.Here we evaluated the performance of metagenomic and amplicon sequencing techniques,and three sequencing platforms in MPXV genome sequencing based on multiple clinical specimens of five mpox cases in Chinese mainland.We rapidly identified the full-length genome of MPXV with the assembly of accurate tandem repeats in multiple clinical specimens.Amplicon sequencing enables cost-effective and rapid sequencing of clinical specimens to obtain high-quality MPXV genomes.Third-generation sequencing facilitates the assembly of the terminal tandem repeat regions in the monkeypox virus genome and corrects a common misassembly in published sequences.Besides,several intra-host single nucleotide variations were identified in the first imported mpox case.This study offers an evaluation of various strategies aimed at identifying the complete genome of MPXV in clinical specimens.The findings of this study will significantly enhance the surveillance of MPXV.

Characterization of whole genomes from recently emerging Mpox cases in several regions of China,2023

Dear Editor,Mpox(formerly known as monkeypox)is a zoonotic disease caused by infection with the monkeypox virus(MPXV).Mpox cases have been sporadic over the past few decades,with outbreaks occurring in only a limited number of countries,primarily as a result of imported cases(El Eid et al.,2022;Tan and Gao,2022).

Molecular Evolution of Protein Sequences and Codon Usage in Monkeypox Viruses

The monkeypox virus(mpox virus,MPXV)epidemic in 2022 has posed a significant public health risk.Yet,the evolutionary principles of MPXV remain largely unknown.Here,we examined the evolutionary patterns of protein sequences and codon usage in MPXV.We first demonstrated the signal of positive selection in OPG027,specifically in the CladeⅠlineage of MPXV.Subsequently,we discovered accelerated protein sequence evolution over time in the variants responsible for the 2022 outbreak.Furthermore,we showed strong epistasis between amino acid substitutions located in different genes.The codon adaptation index(CAI)analysis revealed that MPXV genes tended to use more non-preferred codons compared to human genes,and the CAI decreased over time and diverged between clades,with CladeⅠ>Ⅱa andⅡb-A>Ⅱb-B.While the decrease in fatality rate among the three groups aligned with the CAI pattern,it remains unclear whether this correlation was coincidental or if the deoptimization of codon usage in MPXV led to a reduction in fatality rates.This study sheds new light on the mechanisms that govern the evolution of MPXV in human populations.

A novel method to assess antibody-dependent cell-mediated cytotoxicity against influenza A virus M2 in immunized murine models

The matrix protein 2 (M2) is a preferred target for developing a universal vaccine against the influenza A virus (IAV). This study aimed to develop a method for assessing antibody-dependent cell-mediated cytotoxicity (ADCC) associated with M2-based immunization in mice. We first established a stable cell line derived from mouse lymphoma cells (YAC-1) expressing M2 of H3N2. This cell line, designated as YAC-1-M2, was generated using a second-generation lentiviral tricistronic plasmid system to transduce the M2 gene into YAC-1 cells. The ADCC effect induced by polyclonal antibodies targeting matrix protein 2 ectodomain (M2e) was demonstrated by YAC-1-M2 cell lysis by natural killer cells (NK) derived from mice, in the presence of anti-M2 antibodies obtained from mice immunized with an mRNA vaccine based on M2e. This ADCC effect was found to be stronger compared to the effect induced by monoclonal antibodies (14C2) against M2. Moreover, the ADCC effect was enhanced as the effector-to-target ratio of NK to YAC-1-M2 cells increased. In conclusion, we established a novel method to detect ADCC of M2 of IAV, which paves the way for the development of an M2-based universal vaccine against IAV and an in-depth analysis of its mechanism of broad-spectrum immune protection in mice.

The structural and accessory proteins M,ORF 4a,ORF 4b,and ORF 5 of Middle East respiratory syndrome coronavirus(MERS-CoV)are potent interferon antagonists

The newly emerged Middle East respiratory syndrome coronavirus(MERS-CoV)is a highly pathogenic respira-tory virus with pathogenic mechanisms that may be driven by innate immune pathways.The goal of this study is to characterize the expression of the structural(S,E,M,N)and accessory(ORF 3,ORF 4a,ORF 4b,ORF 5)proteins of MERS-CoV and to determine whether any of these pro-teins acts as an interferon antagonist.Individual structural and accessory protein-coding plasmids with an N-terminal HA tag were constructed and transiently transfected into cells,and their native expression and subcellular localiza-tion were assessed using Wes tern blotting and indirect immunofl uorescence.While ORF 4b demonstrated majorly nuclear localization,all of the other proteins demonstrated cytoplasmic localization.In addition,for the fi rst time,our experiments revealed that the M,ORF 4a,ORF 4b,and ORF 5 proteins are potent interferon antagonists.Further exami-nation revealed that the ORF 4a protein of MERS-CoV has the most potential to counteract the antiviral effects of IFN via the inhibition of both the interferon production(IFN-βpromoter activity,IRF-3/7 and NF-κB activation)and ISRE promoter element signaling pathways.Together,our re-sults provide new insights into the function and pathogenic role of the structural and accessory proteins of MERS-CoV.

A Novel Coronavirus Genome Identified in a Cluster of Pneumonia Cases--Wuhan,China 2019−2020

Emerging and re-emerging pathogens are great challenges to the public health(1).A cluster of pneumonia cases with an unknown cause occurred in Wuhan starting on December 21,2019.As of January 20,2020,a total of 201 cases of pneumonia in China have been confirmed.A team of professionals from the National Health Commission and China CDC conducted epidemiological and etiological investigations.On January 3,2020,the first complete genome of the novelβgenus coronaviruses(2019-nCoVs)was identified in samples of bronchoalveolar lavage fluid(BALF)from a patient from Wuhan by scientists of the National Institute of Viral Disease Control and Prevention(IVDC)through a combination of Sanger sequencing,Illumina sequencing,and nanopore sequencing.Three distinct strains have been identified,the virus has been designated as 2019-nCoV,and the disease has been subsequently named novel coronavirus-infected pneumonia(NCIP).

A novel human mAb (MERS-GD27) provides prophylactic and postexposure efficacy in MERS-CoV susceptible mice

Dear Editor,Since September 2012, the Middle East respiratory syndrome coronavirus (MERS-CoV) cases have been reported in more than 27 countries, and more than 2,000 cases have been confirmed in the laboratory (http://www.who.int/emergencies/mers-cov/en/). MERS-CoV causes an acute and severe respiratory illness with a high mortality rate(~35%) in humans (Shi et al., 2017, Zaki et al., 2012).Neutralizing antibodies targeting the spike of MERS-CoV have been shown to be a therapeutic option for treatment of lethal disease (Agrawal et al., 2016, Ying et al., 2014).

Prevalence and phylogenetic characterization of canine coronavirus from diseased pet dogs in Beijing,China

Dear Editor,Canine coronavirus including canine coronavirus(CCoV)and canine respiratory coronavirus(CRCoV)have been recognized as pathogenic viruses to dogs worldwide,causing enteric and respiratory issues(Buonavoglia et al.,2006).Zoonotic transfer of the viruses from the animal kingdom to humans has been repeatedly observed over the past decade,

The First Imported Case of Monkeypox in the Mainland of China—Chongqing Municipality,China,September 16,2022

Monkeypox is a zoonotic viral disease caused by the monkeypox virus(MPXV),and historically,all outbreaks have been linked to Africa;however,monkeypox has been posing an alarming challenge to the world in 2022(1)as approximately 60,000 cases have been reported in more than 100 nations and regions worldwide(2).Currently,many cases of monkeypox were identified in many nonendemic countries outside of Central and West Africa,and human-to-human transmission has occurred frequently,especially among men who have sex with men(MSM)presenting new clinical symptoms similar to syphilis and other sexually transmitted infections(3).

Summary of the Detection Kits for SARS-CoV-2 Approved by the National Medical Products Administration of China and Their Application for Diagnosis of COVID-19

The on-going global pandemic of coronavirus disease 2019(COVID-19)caused by a novel coronavirus called severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has been underway for about 11 months.Through November 20,2020,51 detection kits for SARS-CoV-2 nucleic acids(24 kits),antibodies(25 kits),or antigens(2 kits)have been approved by the National Medical Products Administration of China(NMPA).Convenient and reliable SARS-CoV-2 detection assays are urgently needed worldwide for strategic control of the pandemic.In this review,the detection kits approved in China are summarised and the three types of tests,namely nucleic acid,serological and antigen detection,which are available for the detection of COVID-19 are discussed in detail.The development of novel detection kits will lay the foundation for the control and prevention of the COVID-19 pandemic globally.

A core-shell structured COYID-19 mRNA vaccine with favorable biodistribution pattern and promising immunity

Although inoculation of COVID-19 vaccines has rolled out globally,there is still a critical need for safe and effective vaccines to ensure fair and equitable supply for all countries.Here,we report on the development of a highly efficacious mRNA vaccine,SW0123 that is composed of sequence-modified mRNA encoding the full-length SARS-CoV-2 Spike protein packaged in core-shell structured lipopolyplex(LPP)nanoparticles.SWOT 23 is easy to produce using a large-scale microfluidics-based apparatus.The unique core-shell structured nanoparticle facilitates vaccine uptake and demonstrates a high colloidal stability,and a desirable biodistribution pattern with low liver targeting effect upon intramuscular administration.Extensive evaluations in mice and nonhuman primates revealed strong immunogenicity of SW0123,represented by induction of Th1-polarized T cell responses and high levels of antibodies that were capable of neutralizing not only the wild-type SARS-CoV-2,but also a panel of variants including D614G and N501Y variants.In addition,SW0123 conferred effective protection in both mice and non-human primates upon SARS-CoV-2 challenge.Taken together,SW0123 is a promising vaccine candidate that holds prospects for further evaluation in humans.

Ferritin nanoparticle-based SARS-CoV-2 RBD vaccine induces a persistent antibody response and long-term memory in mice

To date,the global coronavirus disease 2019(COVID-19)pandemic caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has resulted in more than 90 million people infected and over 2 million deaths.A safe and effective vaccine is in high demand.For an effective vaccine,antibody persistence and longterm memory are favorable features.

The first local case of mpox caused by an imported case in the Chinese mainland

Monkeypox (mpox) is a zoonotic disease caused by the mpox virus (MPXV) that has been primarily limited to Central and West African nations since its discovery. The recent spread of the West African lineage of MPXV in historically unaffected countries has raised concerns for global public health. Despite a significant decrease in global mpox cases, there is still a risk of a global resurgence. This study reports the first local case of mpox caused by an imported case in the Chinese mainland. Polymerase chain reaction (PCR) diagnosed the two cases, and the viral genomes were obtained by next-generation sequencing. Genomic analysis revealed that the two strains shared an identical genome sequence and belonged to the B.1.3 branch of the West African lineage, which is the first local case of mpox caused by an imported case in the Chinese mainland, highlighting the potential threat of mpox in China and the immediate need for adequate surveillance measures.

COVID-19 Outbreak Caused by Contaminated Packaging of Imported Cold-Chain Products—Liaoning Province,China,July 2020

Summary What is known about this topic?Few major outbreaks of coronavirus disease 2019(COVID-19)have occurred in China after major nonpharmaceutical interventions and vaccines have been deployed and implemented.However,sporadic outbreaks that had high possibility to be linked to cold chain products were reported in several cities of China..What is added by this report?In July 2020,a COVID-19 outbreak occurred in Dalian,China.The investigations of this outbreak strongly suggested that the infection source was from COVID-19 virus-contaminated packaging of frozen seafood during inbound unloading personnel contact.What are the implications for public health practice?Virus contaminated paper surfaces could maintain infectivity for at least 17–24 days at-25℃.Exposure to COVID-19 virus-contaminated surfaces is a potential route for introducing the virus to a susceptible population.Countries with no domestic transmission of COVID-19 should consider introducing prevention strategies for both inbound travellers and imported goods.Several measures to prevent the introduction of the virus via cold-chain goods can be implemented.

Evolutionary analysis and lineage designation of SARS-CoV-2 genomes

The pandemic due to the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),the etiological agent of coronavirus disease 2019(COVID-19),has caused immense global disruption.With the rapid accumulation of SARS-CoV-2 genome sequences,however,thousands of genomic variants of SARSCoV-2 are now publicly available.To improve the tracing of the viral genomes’evolution during the development of the pandemic,we analyzed single nucleotide variants(SNVs)in 121,618 high-quality SARS-CoV-2 genomes.We divided these viral genomes into two major lineages(L and S)based on variants at sites 8782 and 28144,and further divided the L lineage into two major sublineages(L1 and L2)using SNVs at sites 3037,14408,and 23403.Subsequently,we categorized them into 130 sublineages(37 in S,35 in L1,and 58 in L2)based on marker SNVs at 201 additional genomic sites.This lineage/sublineage designation system has a hierarchical structure and reflects the relatedness among the subclades of the major lineages.We also provide a companion website(www.covid19evolution.net)that allows users to visualize sublineage information and upload their own SARS-CoV-2 genomes for sublineage classification.Finally,we discussed the possible roles of compensatory mutations and natural selection during SARS-CoV-2’s evolution.These efforts will improve our understanding of the temporal and spatial dynamics of SARS-CoV-2’s genome evolution.