Wuhan Coronavirus Outbreak 2019-20
The 2019 novel coronavirus, also known as 2019-nCoV, is the virus causing the 2019–20 Wuhan coronavirus outbreak. The first suspected cases were officially reported to the WHO on 31 December 2019, with the first instances of symptomatic illness appearing just over three weeks earlier on 8 December 2019. It has subsequently been identified as a positive-sense, single-stranded RNA coronavirus based upon genomic sequencing of a sample from a patient with pneumonia.
The first known outbreak was detected in Wuhan, China, around mid-December 2019. The virus subsequently spread to other provinces of Mainland China and other countries, including Thailand, Japan, Taiwan, South Korea, Australia, and France.
As of 26 January 2020, there are 2,019 confirmed cases, of which 1,979 are within mainland China. The rest are in people who have either travelled to Wuhan, or were in direct contact with someone who travelled from the area. The number of deaths is 56 as of 26 January 2020. Human-to-human spread was confirmed in Guangdong, China, on 20 January 2020.
Reported symptoms have included fever, fatigue, dry cough, shortness of breath, respiratory distress, pneumonia, kidney failure and death in severe cases. Among the majority of those hospitalized, vital signs were stable on admission, and they had low white blood cells, specifically low lymphocytes. However, a quarter of those infected experience severe symptoms. Most of those who have died had weakened immune systems due to underlying health conditions such as hypertension, diabetes or cardiovascular disease.
Animals sold for food are suspected to be the reservoir or the intermediary because many of first identified infected individuals were workers at the Huanan Seafood Market. Consequently, they were exposed to greater contact with animals.
During 17 years of research on the origin of the SARS 2003 epidemic, many SARS-like bat coronaviruses were isolated and sequenced, most of them originating from the Rhinolophus genus. With enough genomes it is possible to reconstruct a phylogenetic tree of the mutation history of a family of virus.
The Wuhan novel coronavirus falls into this category of SARS-related coronaviruses. Two genome sequences from Rhinolophus sinicus with a resemblance of 80% had been published in 2015 and 2017. A third unpublished virus genome from Rhinolophus affinis with a resemblance of 96% to Wuhan novel coronavirus is also mentioned. For comparison, this amount of mutation is similar to amount of mutation observed over 10 years in the H3N2 human flu.
This virus belongs to the family of coronaviruses. Coronaviruses form a large family of viruses, and the illnesses they cause can range from the common cold to more severe diseases such as the Middle East respiratory syndrome (MERS) and severe acute respiratory syndrome (SARS). Coronaviruses are a broad family of viruses, but only six (229E, NL63, OC43, HKU1, MERS-CoV, and SARS-CoV) were previously known to infect people; 2019-nCoV made it seven.
Sequences of Wuhan betacoronavirus show similarities to betacoronaviruses found in bats; however, the virus is genetically distinct from other coronaviruses such as Severe acute respiratory syndrome-related coronavirus (SARS-CoV) and Middle East respiratory syndrome-related coronavirus (MERS-CoV). Like SARS-CoV, it is a member of Beta-CoV lineage B (i. e. subgenus Sarbecovirus). Its RNA sequence is approximately 30 kb in length.
By 12 January, five genomes of the novel coronavirus had been isolated from Wuhan and reported by the China CDC, Institute of Pathogen Biology, and Wuhan Jinyintan Hospital. The number of genomes increased to 28 by 26 January. Except for the earliest GenBank genome, the genomes are under an embargo at GISAID. A phylogenic analysis for the samples is available through Nextstrain.
The publications of the genome has led to several protein modeling experiments on the receptor binding protein (RBD) of the nCoV spike (S) protein. A Chinese group wrote on January 16 that the modelled S protein retains sufficient affinity to the SARS receptor (angiotensin-converting enzyme 2, ACE2) to use it as a mechanism of cell entry. On 22 January, two groups, one in China, working with the full virus; and the other in the U.S., working with reverse genetics, independently and experimentally demonstrated ACE2 as the receptor for 2019-nCoV.
To look for potential drugs, the viral protease M(pro) was also modelled for drug docking experiments. Innophore has produced two computational models based on SARS protease available for download. The Chinese Academy of Sciences produced an experimental structure of a recombinant 2019-nCoV protease on January. The model by Rao ZH and Yang HT's group was not immediately released to the Protein Data Bank.
No specific treatment is currently available, but existing anti-virals are being studied. This includes protease inhibitors like indinavir, saquinavir, remdesivir, lopinavir/ritonavir and interferon beta.
In January 2020, based on the 2019-nCoV published genome, several projects, three supported by the Coalition for Epidemic Preparedness Innovations (CEPI), began work on creating a vaccine for the Wuhan coronavirus. The United States National Institutes of Health (NIH) started cooperating with the biotechnology company Moderna to create a vaccine, hoping to start production by May 2020. Their strategy is to make an RNA vaccine matching a spike of the coronavirus surface. The University of Queensland (UQ; Australia) aims for a molecular clamp vaccine that genetically modifies viral proteins to make them mimic the coronavirus and stimulate an immune reaction. CEPI supports the Moderna and UQ projects and another by Inovio. The Public Health Agency of Canada granted permission to Vaccine and Infectious Disease Organization – International Vaccine Centre (VIDO-InterVac) of the University of Saskatchewan to begin work on a vaccine in an independent project. VIDO-InterVac aims to start production and non-human animal testing in March 2020, and human testing in 2021.