Solved!

So maybe viruses are not that mysterious. The experts are telling us
already. When a virus infects a cell, it is the cell. When it is not in a warm
body, it is inert. There it is: the virus occurs in that moment in evolution when
life needs to replicate the virus and the host, together, to complexify. Voilà!

https://www.sudouest.fr/2020/03/08/que-sont-ils-d-ou-viennent-ils-pourquoi-essaient-ils-de-nous-tuer-que-sait-on-des-virus-exactement-7293350-4696.php

source: SudOuest.fr with AFP

Posted on 08/03/2020

translation: GoogleTransalte/doxa-louise

What are they, where do they come from, why are they trying to kill us: what exactly do we know about viruses?

We touch hundreds of millions of them  every day, but they hold many secrets. What do we know about viruses?

Most viruses catch our attention because they make us sick. But some have beneficial effects. 

They are as old as life itself, but scientists cannot say for sure if they are alive. Viruses are written into our DNA, shaping the human saga through mutation and resistance.

We touch hundreds of millions of them every day. As the new coronavirus epidemic is disrupting global markets and prompting health authorities to take unprecedented containment measures, a very basic question needs to be asked: what exactly is a virus? What are they made of? Where do they come from ? And, perhaps more importantly, why are they trying to kill us?

Unimaginable numbers 

The story of viruses is perhaps best told through mind-blowing figures. Curtis Suttle, a virologist at the University of British Columbia in Canada, says the physical properties of viruses make them difficult to understand.


Their small size, to start with. If each virus in a human body were the size of a pinhead, the average adult would reach 150 kilometers (95 miles) in height. And in a 2018 study, Suttle discovered that more than 800 million viruses are deposited on every square meter of Earth every day. Perhaps more telling, in a tablespoon of seawater, there are generally more viruses than people in Europe.

"We swallow over a billion viruses every time we go swimming. We are inundated with viruses"
Finally, to judge their excessive nature, a 2011 article published in Nature Microbiology estimated that there was more than a quintillion (i.e. a figure with 30 zero) of viruses on Earth. Put them all end to end and they would stretch for 100 million light years, or 1,000 times the width of the Milky Way.

Alive or inert?

According to Teri Shors, professor of biology at the University of Wisconsin Oshkosh and author of several books on the subject, viruses are better thought of as "molecular packages". "These packages must be small enough to fit inside a cell to cause infection."

Essentially chains of genetic material contained by a few protein molecules, viruses occupy a strange middle ground between the living and the inert. Since they have no cells and do not produce energy through respiration - a key definition of living organisms - many scientists do not consider them to be living. However, as soon as they infest their host, viruses enter into activity in a way rarely seen in nature, hacking cells with new genetic instructions to replicate at breakneck speed.

For Ed Rybicki, virologist at the University of Cape Town, viruses are "as much a concept as a thing". "I consider viruses to be alive because when they are in a cell, they ARE the cell." Teri Shors describes viruses as "metabolically inactive". "Unless they can get into a hot body and get inside a cell, viruses are inert."

But once the virus infects its host, "the whole cellular machinery is entirely devoted to the production of viral descendants," remarks Curtis Suttle. "It's the living virus".

Where do they come from ?

Although their beginnings are uncertain, viruses have left their mark on most of life on Earth, including humans. About eight percent of the human genome is of viral origin - that is, the remains of old viruses that infected us, developing tolerance at the species level.

But their story begins long before that of humans. "We think the viruses were there at the very beginning," said Curtis Suttle.

"Whatever primordial soup that gave birth to cell life, it probably gave birth to viral life at the same time"

Are all viruses bad?

Most viruses catch our attention because they make us sick. In recent years, outbreaks of viral infectious diseases have become widespread, from the current epidemic of coronavirus to that of SARS in the early 2000s to Ebola in West and Central Africa.

But there are also virtuous viruses. "Almost all viruses are actually harmless to humans," said Rybicki. Indeed, many viruses are beneficial to human health, infecting other organisms that would otherwise harm us.

Another advantage: the absorption of carbon from oceanic algae, which helps purify the air we breathe, is greatly accelerated by viruses.

And they also have health apps. In addition to vaccines derived from weakened or killed viruses, a new area of ​​treatment, virotherapy, is developing new ways to treat chronic diseases such as cancer. "These viruses replicate in cancer cells but not in healthy cells, so this treatment is not as toxic as conventional cancer therapies," said Teri Shors.

For Rybicki, who has spent most of his professional life trying to unlock their secrets, the most remarkable thing about viruses is the number of mysteries they still hold. "They are the most diverse organisms on our planet (...) and we don't know anything about them yet." The recent discovery of giant viruses shows that they are still capable of surprising us.

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It would be nice to have some closure on this:

https://www.thesun.co.uk/news/11462934/coronavirus-wuhan-lab-russia-microbiologist-claims/