by Antonino Napoleone, Giuseppe Scarlata, Domenico Gangemi | March 28, 2020


On 28th March 2020, 652,079 cases of Coronavirus Disease-19 (COVID-19) are registered worldwide, of which 92,472 only in Italy, which dramatically reaches 10,023 victims since the beginning of the pandemic. The new Severe Acute Respiratory Syndrome Human Coronavirus (SARS-Cov-2) first emerged in Wuhan, China, in December 2019, and it spread to 177 countries around the world in less than 5 months, destabilizing the daily life of millions of people and alarming the public opinion shocked by the exponential increase in the number of infections and by the increase in the number of victims. SARS-Cov-2 is the seventh known coronavirus able to infect humans, preceded by the well-known SARS-CoV and MERS-CoV, and the lesser-known HKU1, NL63, OC43, and 229E. The Wuhan Institute of Virology, founded in 1956 in collaboration with the Chinese Academy of Sciences, represents a worldwide Centre of excellence for the study of human and animal coronaviruses and it has recently been at the middle of a media storm for the presumed bio-engineering of SARS-CoV-2, where the deliberate or accidental spread in the environment would have resulted. The techniques for engineering a microorganism are well established in scientific practice and these are, for example, the basis for the development of many drugs and vaccines in use. These are generally performed starting from the genome (DNA or RNA) of already known and isolated microorganisms, to which experimental modifications are then applied. If SARS-CoV-2 had been created in the laboratory, it would have been easy to identify the laboratory techniques used by scientists to manipulate the virus genome. Furthermore, SARS-CoV-2 is unlikely to have been created in the laboratory for several scientifically proven reasons. Researchers from several countries around the world (including Italy) have isolated the virus, sequenced and analyzed the genome and universally concluded that SARS-CoV-2 originated in nature. According to the renowned journal Nature, the plausible scenario that would explain the virus origin would be the natural selection of the virus in an animal host before transmission in humans. In fact, the SARS-CoV-2 sequence recently published in Lancet shares a high similarity (96%) with the bat coronavirus sequence. Another high similarity was found with the pangolin coronavirus sequence from which SARS-CoV-2 could have jumped species boundaries acquiring mutations that would have increased its virulence in humans.

The similarity with other human coronaviruses such as SARS-CoV and MERS-CoV is 79% and 50% respectively (Figure 1). For instance, if the viral genome of two COVID-19 patients were sequenced, the similarity of these two sequences would be over 99%, so the higher this similarity, the more likely there is a close relationship and/or derivation. The same principle is applicable to the direct connection of the human genome with that of the chimpanzee with 98% similarity, from which the common evolutionary process has been deduced. Where does the idea of connecting the genome of SARS-CoV-2 with that of bats come from? This was discovered by the Chinese scientist Shi Zhengli at the Wuhan Institute of Virology, who has been studying for years the characteristics of these viruses in bats and the possible risk of animal-human transmission. In the midst of a health emergency of this magnitude, it is conceivable that everyone wonders where the viral agent causing the current pandemic originated. The studies mentioned have refuted the widespread theories of manipulation and creation of SARS-CoV-2 in the laboratory, although further researches are needed to fully explain its high contagiousness as well as the mechanisms of animal-human transmission. Share and have faith in medical sciences rather than the media, we all need to work together to stop all of this. 

Figure 1. Phylogenetic tree of all the 2019‐nCov sequences available at 02‐Feb‐2020 (branches shown in blue), plus six Bat coronavirus sequences (default black, as they are split in multiple taxa), six human SARS (green) and two MERS (orange). The percentage of bootstraps supporting each branch is reported. Branches corresponding to partitions reproduced in less than 50% bootstrap replicates are collapsed. MERS, Middle Eastern respiratory syndrome; SARS, severe acute respiratory syndrome.



References:

  1. https://doi.org/10.1038/s41591-020-0820-9
  2. https://coronavirus.jhu.edu/map.html
  3. https://doi.org/10.1016/S0140-6736(20)30251-8
  4. https://doi.org/10.1002/jmv.25700
  5. https://doi.org/10.1080/22221751.2020.1738279 
  6. https://doi.org/10.1016/j.jaut.2020.102434 
  7. https://www.mdpi.com/1999-4915/11/3/210
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