《内科学》课程教学资源（新冠文献）Emerging novel coronavirus（2019-nCoV）current scenario, evolutionary perspective based on genome analysis and recent developments.pdf_大学文库

SHORT COMMUNICATION Emerging novel coronavirus (2019-nCoV)—current scenario, evolutionary perspective based on genome analysis and recent developments Yashpal Singh Malika , Shubhankar Sircara , Sudipta Bhata , Khan Sharunb , Kuldeep Dhamac , Maryam Dadard , Ruchi Tiwarie and Wanpen Chaicumpaf a Division of Biological Standardization, ICAR-Indian Veterinary Research Institute, Bareilly, Uttar Pradesh, India; b Division of Surgery, ICAR–Indian Veterinary Research Institute, Bareilly, Uttar Pradesh, India; c Division of Pathology, ICAR–Indian Veterinary Research Institute, Bareilly, Uttar Pradesh, India; d Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran; e Department of Veterinary Microbiology and Immunology, College of Veterinary Sciences, Deen Dayal Upadhayay Pashu Chikitsa Vigyan Vishwavidyalay Evum Go-Anusandhan Sansthan (DUVASU), Mathura, India; f Center of Research Excellence on Therapeutic Proteins and Antibody Engineering, Department of Parasitology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand ABSTRACT Coronaviruses are the well-known cause of severe respiratory, enteric and systemic infections in a wide range of hosts including man, mammals, fish, and avian. The scientific interest on coronaviruses increased after the emergence of Severe Acute Respiratory Syndrome coronavirus (SARS-CoV) outbreaks in 2002-2003 followed by Middle East Respiratory Syndrome CoV (MERS-CoV). This decade’s first CoV, named 2019-nCoV, emerged from Wuhan, China, and declared as ‘Public Health Emergency of International Concern’ on January 30th, 2020 by the World Health Organization (WHO). As on February 4, 2020, 425 deaths reported in China only and one death outside China (Philippines). In a short span of time, the virus spread has been noted in 24 countries. The zoonotic transmission (animal-to-human) is suspected as the route of disease origin. The genetic analyses predict bats as the most probable source of 2019-nCoV though further investigations needed to confirm the origin of the novel virus. The ongoing nCoV outbreak highlights the hidden wild animal reservoir of the deadly viruses and possible threat of spillover zoonoses as well. The successful virus isolation attempts have made doors open for developing better diagnostics and effective vaccines helping in combating the spread of the virus to newer areas. ARTICLE HISTORY Received 3 February 2020 Accepted 6 February 2020 KEYWORDS Coronavirus; 2019-nCoV; Severe Acute Respiratory Syndrome CoV; Middle East Respiratory Syndrome CoV; Public Health Emergency; genetic analyses; zoonoses; reservoir host; therapeutics; vaccines 1. Introduction Coronaviruses (CoVs) are well-known causes of severe infections, respiratory, enteric and systemic, in humans and numerous animal hosts. The CoV infections have been reported in cattle, swine, horses, camels, rodents, cats, dogs, bats, palm civets, ferrets, mink, rabbits, snake, and several other wild animals and avian species (Fehr and Perlman 2015; Kahn and McIntosh 2005). The coronaviruses of relevant veterinary species are shown in Table 1 with organ affected and clinical signs. Though human CoVs were identified for the first time in the year 1960 from respiratory infections in adults as well as children, the major scientific interest in CoVs research grew only after the emergence of Severe Acute Respiratory Syndrome CoV (SARS-CoV) in the year 2002-2003 (Drosten et al. 2003; Ksiazek et al. 2003; Peiris et al. 2003). In this SARS-CoV epidemic, around 8000 confirmed human cases with 774 deaths (around 9.5% mortality rate) occurred that was a result of its global spread (Kahn and McIntosh 2005). Initially, the virus was detected in the caged Himalayan palm civets and these were thought to be the natural host of this virus (Guan et al. 2003). Following SARS-CoV incidence in 2003, a similar CoV named HKU3-1 to HKU3-3 were identified in the horseshoe bats (non-caged) in 2005 from Hong Kong (Lau et al. 2005). Since then, bats are considered to be the natural host and potential reservoir species that could be held responsible for any future CoVs epidemics and/or pandemics (Cui et al. 2019, Li et al. 2005). After the 2003 and 2005 SARS-CoV epidemics, an analogous virus emerged in the Middle East region of the world leading to severe respiratory illness and was named the Middle East Respiratory Syndrome CoV (MERS-CoV) (Zaki et al. 2012). The mortality was higher than previous SARS-CoV pandemic claiming around 919 lives out of the total 2521 human cases (around 35% mortality) (World Health Organization 2015). Notably, dromedary CONTACT Yashpal Singh Malik malikyps@gmail.com; Kuldeep Dhama kdhama@rediffmail.com; Wanpen Chaicumpa wanpen.cha@mahidol.ac.th Supplemental data for this article is available online at https://doi.org/10.1080/01652176.2019.1697012. 2020 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. VETERINARY QUARTERLY 2020, VOL. 40, NO. 1, 68–76 https://doi.org/10.1080/01652176.2020.1727993

camels were connected with the transmission of MERS-CoV (Alagaili et al. 2014). Further, its origin was also traced from bats (Ithete et al. 2013). All these highly pathogenic human CoVs, SARS and MERS, show emergence over wider areas of the world posing high risk of human-to-human transmission and fatal consequences thereto (Figure 1). This decade’s first CoV emergency was from Hubei province of China, and as on February 4, 2020, 425 deaths have been reported in China only (World Health Organization 2020b). Further, the spread of this novel coronavirus, named 2019-nCoV, has been noted in 24 countries till date. Considering the global threat of the 2019-nCoV, the World Health Organization (WHO) declared it as a ‘Public Health Emergency of International Concern’ on January 30th, 2020. This rapid communication provides an overview of the recently emerging coronavirus (2019-nCoV) with regards to its current scenario, comparative analysis with respects to previously reported CoVs, evolutionary perspective based on genome analysis while covering the recent advances on vaccines and therapeutics in brief. Table 1. Coronaviruses of relevant veterinary species. Host Virus Genus Organ affected Clinical sign Bovine Bovine coronavirus Betacoronavirus GI Tract Respiratory tract Calf diarrhea Winter dysentery (bloody diarrhea) in adult cattle Bovine respiratory disease complex (shipping fever) Porcine Transmissible gastroenteritis (TGE) virus Alphacoronavirus GI Tract Profuse watery yellow diarrhea, Vomition, dehydration Porcine respiratory coronavirus Alphacoronavirus Respiratory tract Mild respiratory disease or subclinical Porcine epidemic diarrhea virus (PEDv) Alphacoronavirus GI Tract Watery diarrhea, vomition, dehydration Porcine hemagglutinating encephalomyelitis virus Betacoronavirus GI Tract CNS Vomition, Diarrhea Wasting disease Encephalomyelitis Porcine deltacoronavirus Deltacoronavirus GI Tract Gastroenteritis Feline Feline enteric coronavirus Alphacoronavirus GI Tract Mild gastroenteritis and diarrhea Feline infectious peritonitis virus Alphacoronavirus Respiratory tract Abdominal cavity CNS Pneumonia Peritonitis Neurological disorder Canine Canine coronavirus Alphacoronavirus GI Tract Mild to severe gastroenteritis Canine respiratory coronavirus Betacoronavirus Respiratory tract Kennel cough Pneumonia Equine Equine coronavirus Betacoronavirus GI Tract Gastroenteritis Camel Middle East respiratory syndrome (MERS) coronavirus Betacoronavirus Respiratory tract Mild respiratory signs Chicken Avian infectious bronchitis virus Gammacoronavirus Trachea Kidney Reproductive tract Tracheobronchitis, Rales Nephritis Decreased egg production Figure 1. World-map depicting countries with SARS-CoV and MERS-CoV outbreaks. Red and yellow colors represent the global distribution of only MERS-CoV and SARS-CoV, respectively. The yellow-red dotted pattern shows the incidence of both viruses in the countries. VETERINARY QUARTERLY 69

70Y.S.MALK ET AL 2.Coronaviruses the Chinese Center for Disease Control and Prevention (CDC)that a new coronavirus has emerged and wa 95 named 20 idae and the order single-stranded positive-sense rNa genome ranging ere cases of 2019-nCoV.In addition to China,24 dif from 26 to 32kb in length(the largest genome of ferent countries from Europe,Northern America known RNA viruses)with G+C contents varying from Southeast Asia,Eastern Mediterranean,and Westerr 32to43% ic structure ana phylo dis cas gene Betacoronavirus. and 2019nC the earlier outbreaks of SARS and MERS-CoVs,as Deltacoronavirus.Among these Alphacoronavirus and as this virus presents relatively mild manifestations ronavirus infects only ma the total number of cases are increasing speedily and are cros ssing the old census.There is a high risk of ruses.SARS-CoV and MERS-CoV belong to the g um wh as als Betacoronavirus.The genus Betacoronavirus further mily distributed in five subgenus among which ea with hest radiographs show g acute inva e Groot sive lesions in both lungs. ,2012 Hihe The nCov contains at least six open reading frames (ORFs)and many other accessory genes like other Currently.knowledge about the origin of the viru (ORFs its particular receptor,clinical spectrum and host ecies preference is unknown.World over scientists which is further ceaved into 11 and 16 aged in unraveling th e genomi nature o respectively.These 16 mature proteins are responsible now,aro 15 for several important function nCoV genom 5 USA) ance and ruc usage analysis speculated snakes to be its natural (E)mem host,whereas several subsequent reports after that one-third a'to mminal of the a ome In addition to oublication rejected this hypothesis They found the members to be Bat_SARS-like CoVs (Bat-SL 5,N lysis 34)in phylogenetic ana the most important genes for receptor binding and HE)om 4.1.Analysis targeting the complete genome of 2019-nCoVs 3.The emergence of novel-Coronavirus also atte (2019-nco) npted to reveal the of th 201g During the first week of Dec the complete Hube Phylogenetic analysis was done using the MEGA 7.0 province of China.The patients exhibited a history of applying the Maximum likelihood method visiting the local nearby Huanan seafood market ML Reversible substitutio which deals in the sale of different live the where zoo anima 201 28h2020 of th 2020).Firstly,the affected patients pre nted witl urrent 2019-ncoy outbreak sequences as calc pneumonia-like symptoms,followed by a severe lated using the MegAlign software of DNASTAR.In acute respiratory infection.Some cases showed rapid whole genome phylogenetic analysis,the 2019 cute respiratory distress syndrome CoV strains s from China and the USA clustered in a ARDS) h

2. Coronaviruses Coronaviruses (CoVs) constitute a large family of viruses found in nature. CoVs belongs to the family Coronaviridae and the order Nidovirales possessing a single-stranded, positive-sense RNA genome ranging from 26 to 32 kb in length (the largest genome of known RNA viruses) with G þ C contents varying from 32 to 43%. Based on the genomic structure and phylogenetic analysis the subfamily Orthocoronavirinae consists of four genera namely Alphacoronavirus, Betacoronavirus, Gammacoronavirus and Deltacoronavirus. Among these Alphacoronavirus and Betacoronavirus infects only mammals and are responsible for respiratory infection in humans and enteritis in animals. Two major zoonotic pathogenic coronaviruses, SARS-CoV and MERS-CoV belong to the genus Betacoronavirus. The genus Betacoronavirus further distributed in five subgenus among which Sarbecovirus contains SARS-CoV and the novel coronavirus (2019-nCoV) (de Groot et al. 2012). The other subgenera under Betacoronavirus are Embecovirus, Hibecovirus, Merbecovirus, and Nobecovirus. The nCoV contains at least six open reading frames (ORFs) and many other accessory genes like other CoVs. The 50 terminal two-thirds of the genome contains two open reading frames (ORFs), ORF1 and ORF2 which encodes two polyproteins, pp1a and pp1ab, which is further cleaved into 11 and 16 proteins, respectively. These 16 mature proteins are responsible for several important functions in genome maintenance and virus replication. The structural proteins namely spike (S), an envelope protein (E), membrane protein (M) and nucleocapsid (N) are located at the one-third 30 terminal of the genome. In addition to these genes, there are several accessory proteins which help in virus replication. The S gene is one of the most important genes for receptor binding and host specificity. Some coronaviruses have hemagglutinin-esterase (HE) protein in their virion. 3. The emergence of novel-Coronavirus (2019-nCoV) During the first week of December 2019, a few cases of pneumonia appeared in the city of Wuhan, Hubei province of China. The patients exhibited a history of visiting the local nearby Huanan seafood market which deals in the sale of different live animals, where zoonotic (animal-to-human) transmission suspected as the main route of disease origin (Hui et al. 2020). Firstly, the affected patients presented with pneumonia-like symptoms, followed by a severe acute respiratory infection. Some cases showed rapid development of acute respiratory distress syndrome (ARDS) followed by serious complications in the respiratory tract. On Jan 7th, 2020, it was confirmed by the Chinese Center for Disease Control and Prevention (CDC) that a new coronavirus has emerged and was named 2019-nCoV. As on February 4th 2020, China has confirmed 20471 cases with 425 deaths and 2788 severe cases of 2019-nCoV. In addition to China, 24 different countries from Europe, Northern America, Southeast Asia, Eastern Mediterranean, and Western Pacific Asia have reported the confirmed cases of this disease making the total tally of confirmed cases to 20630 worldwide (Figure 2). Although the mortality rate due to 2019-nCoV is comparatively lesser than the earlier outbreaks of SARS and MERS-CoVs, as well as this virus presents relatively mild manifestations, the total number of cases are increasing speedily and are crossing the old census. There is a high risk of human-to-human transmission which has also been reported in family clusters and medical workers. The infected patients with nCoV exhibit high fever and dyspnea with chest radiographs showing acute invasive lesions in both lungs. 4. Phylogenetic analysis and sequence identity Currently, knowledge about the origin of the virus, its particular receptor, clinical spectrum and host species preference is unknown. World over scientists are engaged in unraveling the genomic nature of this virus. As of now, around 15 complete 2019- nCoV genome sequences (10 China and 5 USA) have been reported. To note, a report based on the codon usage analysis speculated snakes to be its natural host, whereas several subsequent reports after that publication rejected this hypothesis. They found the nearest members to be Bat_SARS-like CoVs (Bat-SLCoVs, MG772933 & MG772934) in phylogenetic analysis within the subgenus Sarbecovirus. 4.1. Analysis targeting the complete genome of 2019-nCoVs In this study, we also attempted to reveal the evolutionary perspective of the recently emerging 2019- nCoV based on the complete genome analysis. Phylogenetic analysis was done using the MEGA 7.0 version applying the Maximum likelihood method (ML) based General Time Reversible substitution model with the available whole genome sequences of 2019-nCoV available in the NCBI GenBank database till January 28th, 2020. Pairwise identity of the current 2019-nCoV outbreak sequences was calculated using the MegAlign software of DNASTAR. In the whole genome phylogenetic analysis, the 2019- nCoV strains from China and the USA clustered in a monophyletic clade (Figure 3). The nearest neighbors of the 2019-nCoV isolates from China and USA were 70 Y. S. MALIK ET AL

4.2. Analysis targeting the spike (S)-gene of CoVs We furthermore extended the analysis targeting the Spike (S) glycoprotein gene of the CoVs from human SARS, animal-origin CoVs including MERSV (camel), bovine coronavirus, canine coronavirus, bat_coronaviruses and the current outbreak nCoVs from different regions. The sequences of nCoV available in the NCBI GenBank database till January 28th, 2020 were retrieved. Phylogenetic analysis was done using the MEGA 7.0 version applying the Maximum likelihood method (ML) based General Time Reversible substitution model with gamma distribution. Pairwise identity of the current 2019-nCoV outbreak sequences was calculated using the MegAlign software of DNASTAR. In the S-gene based phylogeny, 10 Chinese and 5 USA nCoV isolates (Figure 4) revealed that all the isolates are nearly identical across the Sgene based phylogeny constituting a monophyletic clade (Figure 4). The two Bat_SARS-like CoVs (Bat-SLCoVZC45, MG772933 and bat-SL-CoVZXC21, MG772934) shared 100% bootstrap support with 2019-nCoV isolates of the current outbreaks. Based on the MegAlign and MEGA 7.0 software based Clustal W alignments, the sequence identity of 2019-nCoV strains revealed Bat SARS-like CoVs (Bat-SL-CoVZC45, MG772933 and bat-SL-CoVZXC21, MG772934) as the nearest neighbors with 77.6 to 78.2% sequence identity on nucleotide basis. In the phylogenetic tree, the current outbreak nCoV isolates were fairly distinct than the previously reported SARS-CoV or BatSARSCoV strains but were clustering inside a common major clade which includes strains from subgenus Sarbecovirus. The per cent identity with other SARSCoV or BatSARS-CoV strains was 70.8 to 74.7% (Supplementary data 1). The per cent similarity on nucleotide basis between nCoV isolates and canine respiratory coronaviruses (CRCoV) and bovine coronaviruses (BCoV) of subgenus Embecovirus ranged between 40.8 to 41.5%. Furthermore, the per cent identity of nCoV isolates was found lower (40.2%) with the mild respiratory human coronavirus isolate HCoV-OC43 of same subgenus Embecovirus containing animal-origin coronaviruses. Figure 4. Spike (S) glycoprotein gene-based phylogenetic analysis of 2019-nCoV isolates (10 Chinese and 5 USA isolates). The 2019-nCoV isolates analyzed with related CoVs from past human outbreaks and of animal-origin including MERSV (camel), bovine coronavirus, canine coronavirus, bat_coronaviruses. The solid-black circles are for nCoV isolates from China and the USA. 72 Y. S. MALIK ET AL

VETERINARY QUARTERLY⊙乃 pplb 1 ireGenome of novelcronirs Comparative pike (5)proteinseqence length of diferent Additionally,for S-gene,per cent similarity range past de ades.But the degree of cross-protection pro patter was eva ted amin acid ba by s vaccines s greatly limited due to 0199 and US 81 8%6 and 77 0 to 78 196 for 2019-nCov isolate 013 As for MERS and SAp Bat SARS-like Covs and other SABS like Covs there is no licensed specific antiviral t respectively.The per cent identity with human cor- vaccine available till now.However.few of the onavirus isolate HCoV-OC43 was also found lower advan in developing vaccines and ther (28.0%)(Supplementary data 2) eutic SARS-CoV and ERS-Co nuc sed per 20于m h t to tackle thepr genetic tree the 2019-nCov isolates classified insub navirus pa would take some time,therefore genus Sarbecovirus and the sequences from CRCov, till then we need to rely extensively on enforcing BCoV and HCoV-OC43 isolates clustered in subgenus ffective pre tion and control n Embecovirus nov the enomic analysis. the gene of 2019 of th with othe e in snike fo encoded by 2019-nCoy compared with the Bat ein or s tein (Graham et al.2013).This is mainl SARS-like CoVs,SARS-CoV,and MERS-CoV is depicted because of the fact S protein s the majo in Figure 5.The length of 'S'protein of nCoV is l nducer eutralizing antib (Jiang et a ids)tha ner tw virus (SAR nd ar tiviral ugs that ar -12 Cov ha det. full-lenath s protein viral vecto ased ya at the N-terminal region.along with four changes in cine,DNA-based vaccine, recombinant s protein the receptor binding motif inside the receptor bind- based and recombinant RBD protein-based vaccines ing domain in comparison with SARS-CoV (Zhou Whereas S protein based antiviral therapi et al.2020).Several previous studies have shown the ACE2 hib to th Du e 200 SARS-CoVs hav options have proven efficacy in the in vitro studie most of these haven't undergone random and Munster 2020).A recent finding proves that the animal or human trials and hence are of limite binding capacity of nCov S'protein with humar ent ACE2 is the nanto-numa o an 2020 disease.It also has anti-coronavirus activity due its inhibitory action on the SARS-CoV and MERS-Cov replication (Sheahan et al.2017).At present,effort 5.Advances and prospects in developing vaccines and therapeutics are being made to identify and develop monodlona s have been at are therapy a93C0 d

Additionally, for S-gene, per cent similarity range pattern was evaluated in amino acid based index where 2019-nCoV isolates from China and USA were 100% identical. The range varied between 81.2 to 81.8% and 77.0 to 78.1% for 2019-nCoV isolates with Bat_SARS-like CoVs and other SARS like CoVs, respectively. The per cent identity with human coronavirus isolate HCoV-OC43 was also found lower (28.0%) (Supplementary data 2). Overall, the nucleotide and amino acid based per cent identities indicate toward highly diverged nature of novel coronaviruses. To note, in the phylogenetic tree the 2019-nCoV isolates classified in subgenus Sarbecovirus and the sequences from CRCoV, BCoV and HCoV-OC43 isolates clustered in subgenus Embecovirus. In the genomic analysis, the S gene of 2019- nCoVs was found to exhibit lower sequence identity with other Betacoronaviruses. Difference in spike protein encoded by 2019-nCoV compared with the Bat SARS-like CoVs, SARS-CoV, and MERS-CoV is depicted in Figure 5. The length of ‘S’ protein of nCoV is longer (1282 amino acids) than other two viruses (SARS- 1255 amino acid and BatSL-1246 amino acids) under the same Sarbecovirus subgenus. The ‘S’ protein of nCoV has been detected with three short insertions at the N-terminal region, along with four changes in the receptor binding motif inside the receptor binding domain in comparison with SARS-CoV (Zhou et al. 2020). Several previous studies have shown the usage of different receptors for CoVs like human ACE2 for SARS-CoV and CD26 for MERS-CoV (Lu et al. 2020). Identical motifs and residues to that of SARS-CoVs have been identified in the nCoV, yet they show divergence based on phylogeny (Letko and Munster 2020). A recent finding proves that the binding capacity of nCoV ‘S’ protein with human ACE2 is as efficient as SARS-CoV, which further promotes the human-to-human transmission (Letko and Munster 2020). 5. Advances and prospects in developing vaccines and therapeutics Several attempts have been made to develop vaccines against human coronavirus infection in the past decades. But the degree of cross-protection provided by such vaccines is greatly limited due to the extensive diversity in antigenic variants even within the strains of a phylogenetic sub-cluster (Graham et al. 2013). As for MERS and SARS coronaviruses, there is no licensed specific antiviral treatment or vaccine available till now. However, few of the advances made in developing vaccines and therapeutics for SARS-CoV and MERS-CoV could be exploited for the countering 2019-nCoV. But since the efforts to design and develop any vaccine or antiviral agent to tackle the presently emerging coronavirus pathogen would take some time, therefore till then we need to rely extensively on enforcing highly effective prevention and control measures to minimize the risk of 2019-nCoV transmission and spread to the best feasible extent (Cheng et al. 2020). Majority of the vaccines that are being developed for coronaviruses targets the Spike glycoprotein or S protein (Graham et al. 2013). This is mainly because of the fact that S protein is the major inducer of neutralizing antibodies (Jiang et al. 2005). Several kinds of vaccines and antiviral drugs that are based on S protein have been previously evaluated. Among them, the S protein-based vaccines include full-length S protein vaccines, viral vector-based vaccine, DNA-based vaccine, recombinant S proteinbased and recombinant RBD protein-based vaccines. Whereas S protein based antiviral therapies include RBD–ACE2 blockers, S cleavage inhibitors, fusion core blockers, neutralizing antibodies, protease inhibitors, S protein inhibitors, and small interfering RNAs (Du et al. 2009). Even though such therapeutic options have proven efficacy in the in vitro studies, however most of these haven’t undergone randomized animal or human trials and hence are of limited use in our present 2019-nCoV scenario. Remdesivir is a novel nucleotide analog prodrug that was intended to be used for the treatment of Ebola virus disease. It also has anti-coronavirus activity due to its inhibitory action on the SARS-CoV and MERS-CoV replication (Sheahan et al. 2017). At present, efforts are being made to identify and develop monoclonal antibodies that are specific and effective against 2019-nCoV. Combination therapy with 2019-nCoV specific monoclonal antibodies and remdesivir can Figure 5. Genome organization of novel coronavirus. Comparative spike (S) protein sequence length of different Betacoronaviruses is depicted. VETERINARY QUARTERLY 73

74④Y.5.MALK ET AL be considered as the ideal therapeutic option for altogether would pave ways for designing effective 2019n0 (Coher 2020 Further ev luation prevention and control measures to counte fore connrming th ne emcacy of such con 2019-nCoV ainst co ruses are being explored and vet to be evaluated in 7.Conclusion and future prospects terms of their potency,efficacy and safety,but hope- The nCov is the most recently emerging virus after fully the process of evaluation will be accelerated in the episodes and par s haunted by Ebola,Zik 2020;Lu 2020;Pillaiyar uses, Bird 6.Prevention and control measures loba vithi a shor of ti prigin from Wuban.Hubei i nro ince of China in the Seeing the possible of animals in 2019-nCol first week of December 2019,it has claimed 425 lives infecti HO in its adv e for pub in China and infected 20630 in 24 countries includ ng China.Additionally,new cases are emerging ir countries anc three confirmed cases fror eme vide chances to animal CoVs to get transmitted to on or this pap humans and these markets may act as critical places for the nov pathogens and pose rted for the first time outside China The higl risis has heen declared as'public Heatth Em of International Concern'by wHO.The zoonoti oute (animal-to-human)is suspected as the route of and animal health sectors.Other effective measures disease origin.Bats are considered as the natural res One health approach, hosts and role include in transmitting implementation ngE P evention cont stra 》 s in rking SARS-CO nid and nhancina dis ruses has been found in the circulatin ease surveillance and monitoring implementation of bats of Westem Europe(Gouilh et al.2018).The ge strict biosecurity measures,and etic analyses predict bats as the most probable ori timely efforts toward opriate and ain of 2019-nCoV.The diversity of Covs in the bat designing appr vaccines populatio needs further inve stigation in details erape 202 2017 as the monitorin ba taL.20171 event future In the present scenario of not having any direct acting anti-viral agent and vaccines,strict implemen s the tation of high vigilance for 2019-nCoV and appropri and possible threat of spillove Successful virus isolation attemnts have made doo ate prevent asures f utmo open for developing better diagnostics and effective of this vaccines.A report emerged from China where the Authorities (WHO.CDC Atlanta and others)acros cientists claime isolation of the 2019 the alobe are working to combat the current nCoV virus in Ve nd Hu e ongoing 2019-nCoV outbreaks,identifying the pos ub sible origin of this novel virus,and to design Tha 20 2020 Institute for Infection and Immunity at Melbourn virs in do Australia,were also successful in growing the Wuhan and immunoloay adantive genetic changes muta coronavirus in cell culture.Further research is war tions and recombination events,elucidating clinical ranted on establishing animal models for the curren pathology and pathogenesis,identifying the route of 2019-nCoV unrevealing viral events of replication origin, role of any mixing vessels (like birds,pigs missio and pa esis in h and man pro or discovering effec thera

be considered as the ideal therapeutic option for 2019-nCoV (Cohen 2020). Further evaluation is required before confirming the efficacy of such combination therapy. A variety of different therapeutic and vaccine designing approaches against coronaviruses are being explored and yet to be evaluated in terms of their potency, efficacy and safety, but hopefully the process of evaluation will be accelerated in the coming days (Cyranoski 2020; Lu 2020; Pillaiyar et al. 2020; Zaher et al. 2020). 6. Prevention and control measures Seeing the possible role of animals in 2019-nCoV infection, WHO in its advice for public recommended to avoid the unprotected contact with both farm and wild animals (World Health Organization 2020a). The live-animal markets such as in China could provide chances to animal CoVs to get transmitted to humans and these markets may act as critical places for the origin of novel zoonotic pathogens and pose high public health risks during an outbreak. The emergency pathogens could be counteracted by opting immediate and timely international collaborative efforts, cooperative efforts between human and animal health sectors. Other effective measures include One health approach, implementation of effective prevention and control strategies, rapid communication and networking, and exploring advances in science and technology for developing rapid and confirmatory diagnostics, enhancing disease surveillance and monitoring, implementation of strict biosecurity measures, and timely efforts toward designing appropriate and effective vaccines and therapeutics (Cheng et al. 2020; Cohen 2020; Cyranoski 2020; Lu 2020; Munjal et al. 2017; Singh et al. 2017). In the present scenario of not having any direct acting anti-viral agent and vaccines, strict implementation of high vigilance for 2019-nCoV and appropriate prevention and control measures are of utmost importance to check the further spread and control of this virus (Cheng et al. 2020). Researchers and Authorities (WHO, CDC Atlanta and others) across the globe are working to combat the current ongoing 2019-nCoV outbreaks, identifying the possible origin of this novel virus, and to design and develop effective vaccines and therapeutics (Cohen 2020, Cyranoski 2020, Lu 2020, Mahase 2020). Studying the virus in details, its molecular biology and immunology, adaptive genetic changes, mutations and recombination events, elucidating clinical pathology and pathogenesis, identifying the route of origin, role of any mixing vessels (like birds, pigs, and mammals), jumping the species barrier, zoonotic potential, human-to-human transmission events, altogether would pave ways for designing effective prevention and control measures to counter 2019-nCoV 7. Conclusion and future prospects The nCoV is the most recently emerging virus after the past episodes and panics haunted by Ebola, Zika and Nipah viruses, as well as earlier emergencies posed by Bird flu and Swine flu viruses. The emerging novel coronavirus (2019-nCoV) has become a global concern within a short span of time. Since its origin from Wuhan, Hubei province of China in the first week of December 2019, it has claimed 425 lives in China and infected 20630 in 24 countries including China. Additionally, new cases are emerging in different countries and three confirmed cases from India also emerged till compilation of this paper, February 4th, 2020. As of now deaths were reported only from China but now causality in Philippines reported for the first time outside China. The nCoV crisis has been declared as ‘Public Health Emergency of International Concern’ by WHO. The zoonotic route (animal-to-human) is suspected as the route of disease origin. Bats are considered as the natural reservoir hosts and play a crucial role in transmitting various viruses, including Ebola, Nipah, Coronavirus and others (Cui et al. 2019). A high diversity among zoonotic Alphacoronaviruses and SARS-CoV-related Betacoronaviruses has been found in the circulating bats of Western Europe (Gouilh et al. 2018). The genetic analyses predict bats as the most probable origin of 2019-nCoV. The diversity of CoVs in the bat population needs further investigation in details, as well as the surveillance and monitoring of bats becomes critical to prevent future outbreaks in animals and the public. The recent nCoV outbreak highlights the hidden wild animal reservoir of the deadly viruses and possible threat of spillover zoonoses. Successful virus isolation attempts have made doors open for developing better diagnostics and effective vaccines. A report emerged from China where the scientists claimed successful isolation of the 2019- nCoV virus in Vero and Huh7 cell lines from infected patients. Subsequently, in aiding the further research for designing rapid diagnostics and vaccine development for nCoV, scientists at The Peter Doherty Institute for Infection and Immunity at Melbourne, Australia, were also successful in growing the Wuhan coronavirus in cell culture. Further research is warranted on establishing animal models for the current 2019-nCoV unrevealing viral events of replication, transmission, and pathogenesis in humans. This could provide clues for discovering effective therapeutic regimens and vaccine testing purposes 74 Y. S. MALIK ET AL

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