ABSTRACT
The origin of SARS-CoV-2 is uncertain. Findings support a "bat origin" but results are not highly convincing. Studies found evidence that SARS-CoV-2 was around for many years before the pandemic outbreak. Evidence has been published that the progenitor of SARS-CoV-2 already had the capability to bind strongly to the human ACE2 receptor. This may be an indication that many other animal viruses are capable to jump to humans, having already affinity for a human receptor. This is quite worrying since current ecosystems' collapse brings people to high proximity with animals, increasing probabilities for random viral transitions. On the other hand, future adaptation of SARS-CoV-2 is of great concern. Virus-host interactions are complicated and unfortunately, we still do not have accurate tools for predicting viruses' future evolution. Viral adaptation is a multifactorial process and probably SARS-CoV-2 will not become soon, as we wish, a harmless infection. However, humanity is currently under the largest vaccination program and it's of great interest to see if vaccinations will change the evolutionary game against the virus.
Subject(s)
COVID-19 , SARS-CoV-2 , Animals , COVID-19/epidemiology , Ecosystem , Humans , Pandemics , Spike Glycoprotein, Coronavirus/metabolismABSTRACT
Transmission of viruses from one species to another is not unusual in nature. Despite this, evolutionarily successful transmissions are rare. Such events can cause pandemics and are followed by host-virus coevolution procedures that can increase the fitness potential of viruses. In this perspective article, I recognize eight main types of trans-species viral transmission. I consider two of them as evolutionarily successful, explaining why coronavirus SARS-CoV-2 could be one of them.