More about coronavirus

Back in the 2007 Cheng et al. clearly stated the potential risk of suffering another coronavirus outbreak “Coronaviruses are well known to undergo genetic recombination, which may lead to new genotypes and outbreaks. The presence of a large reservoir of SARS-CoV-like viruses in horseshoe bats, together with the culture of eating exotic mammals in southern China, is a time bomb”. But as in most disaster movies the scientist were severely and unsurprisingly ignored.

While this new outbreak is not as deadly as the 2007 SARS was, it is very concerning how fast it has spread all across the globe. Even if Africa where until few days ago the Covid-19 cases were scarce, already 4000 people were tested positive, and I cannot help wondering whether there are not more cases due the poor health system that present most African countries. I recently saw a meme that stated the following: the rich will die from Covid-19, the poor from atypical pneumonia. In any instance, Europe has found itself in an almost complete quarantine and the US which had, literally, two weeks ago only 15 cases registered, now leads the number of cases — it is already over 120.000. The private nature of the US health system makes the fight against the virus harder and the World Health Organization have already warned of USA becoming a coronavirus epicenter.

During the first weeks of the pandemic there was a rumor regarding the laboratory origin of the SARS-CoV-2 —the official name of the virus—, based mainly on the fact of the existence of a Biosafety Level 4 laboratory in the city of Wuhan. Some people went even further by asserting that this was some kind of international conspiracy. Unsurprisingly, recent investigations have addressed that is improbable that SARS-CoV-2 emerged through laboratory manipulation of a related SARS-CoV-like coronavirus. Instead, Andersen et al. proposed two alternatives: (i) natural selection in an animal host before zoonotic transfer; and (ii) natural selection in humans following zoonotic transfer.

In either case a zoonotic transfer is needed. It has been reported that both bats and pangolins are natural reservoirs of SARS-CoV-2 coronaviruses. Whereas bats share a bigger proportion their genome sequence with SARS-CoV-2, it might not be the immediate ancestor of SARS-CoV-2 because it is not predicted to use the same cell receptor used by SARS-CoV-2. A group of coronaviruses found in the endangered species of small mammals known as pangolins, which are often consumed as a source of meat in southern China, have been predicted to interact with this very receptor. Aside from RatG13, Pangolin-CoV is the most closely related CoV to SARS-CoV-2.

All in all, while SARS-CoV-2 coronavirus is known to be a result of the natural selection and not product of genetic engineering, its exact origin is still unknown. In addition, the following days and weeks we will observe a remarkable increase in the number of cases —and hence the deaths— worldwide. In the meantime, Trump keeps saying that US workers should keep working, giving us the chance to do some fabulous dark jokes about him and his management.