SARS-CoV-2 (formerly known by the provisional trade name 2019-nCoV or as Wuchan coronavirus, sometimes also a new coronavirus) is a taxonomic strain or intraspecific positive of a viral species with the international taxonomic name Severe acute respiratory syndrome-related coronavirus. It is an RNA coronavirus that causes covid-19 (coronavirus disease 2019), which was first observed in late 2019 in the Chinese city of Wuchan. It is now the eighth known human coronavirus. Sequence analysis revealed that it belonged to the same species as SARS-CoV, the virus that causes SARS. The new virus differs from SARS-CoV in the sequence of some viral proteins that suppress antiviral immunity and activate inflammatory disease. The disease appeared in 220 countries around the world, including the Czech Republic. By October 23, 2021, a total of 243,657,129 cases had been confirmed in 195 countries, including 4,947,967 deaths attributed to covid-19. On the same day, 6,742,578,222 people received vaccinations.
Since its first appearance in Europe in February 2020, a mutation in the human population, known as D614G, has probably predominated in the human population, most likely originating in the United Kingdom. This mutation in the spike protein gave the virus a selection advantage, which is manifested by easier transmission and faster replication in the ciliated cells of the respiratory tract epithelium. The updated occurrence of various forms (mutations) of the virus in the Czech Republic can be monitored in the database managed by the Institute of Molecular Genetics of the ASCR, v.v.i.
On December 31, 2019, the Wuhan City Health Commission announced that there were a number of patients with symptoms of pneumonia of unknown origin in the city. Some of the patients were sellers and traders at a local market for live animals and seafood from southern China, where raw meat intended for human consumption came into contact with live animals. Nutcrackers have been considered as one of the possible intermediate hosts or a source of complementary virus, but later research has clearly refuted this theory. the pandemic does not sufficiently explain the origin of the virus and escape from the laboratory remains a likely option to be investigated. The market in Wuhan was only a secondary outbreak where infected people were infected. By comparing the published sequences of SARS-CoV-2 from the beginning of the pandemic with the frequency of virus mutations, a common ancestor of these variants was derived, which began to spread exponentially as early as November 2019. Virus phylogeny also clearly excluded legumes as intermediate hosts. Fifteen patients were reported to be a new type of coronavirus, as confirmed by the World Health Organization two days later. After several members of the medical staff involved in the care of the infected became ill, it became clear that the virus was transmissible from person to person. The genome of the virus has also been published and is now available through the European Global Catalog for Virus Archiving and the NCBI Gene Archive. The first case of an outbreak outside China was reported in Thailand. The infected later reported, among others, Japan, Taiwan, the USA and Singapore. The number of infected is growing rapidly. In January 2020, covid-19 spread to the remaining inhabited continents, including Europe. In the Czech Republic, the infection was confirmed on 1 March 2020.30. January 2020 was announced by the World Health Organization