• Question: How are virus created?

    Asked by anon-256945 on 16 Jun 2020.
    • Photo: Martin Coath

      Martin Coath answered on 16 Jun 2020:

      Viruses occur naturally as part of the same processes that produced all other forms of life. It is true that viruses are very simple and people have argued long and hard about if viruses are truly ‘alive’. But whatever you think about that argument, they are a common part of the web of life over the whole planet.

    • Photo: Anabel Martinez Lyons

      Anabel Martinez Lyons answered on 16 Jun 2020: last edited 16 Jun 2020 8:03 am

      Thanks for your question, Iago! As Martin has said, viruses are seen as a ‘simple’ unit of life, composed of protein on the outside, and a small set of genetic information on the inside (unlike humans that have more than 20,000 genes, viruses can have as few as 8!). They cannot replicate (make more of themselves) without help, and instead need to use a host cell’s replication machinery to ‘create’ more virus. They do this by binding to proteins on a host cell’s surface, being engulfed into the cell and travelling along the cytoskeleton of the cell to its genetic centre (called the nucleus). Here, the virus’s protein outer layer is broken down and the genetic information is inserted into the nucleus; it is then copied and ‘read’ like all our normal genes, eventually leading to creation of more viral proteins and therefore the creation of many more viruses. For every one virus that infects a host cell, thousands more can be created and go on to infect and kill other cells in an organism. This is how they can spread so quickly and so widely! Hope that helps answer your question 🙂 .

    • Photo: Luke Hillary

      Luke Hillary answered on 16 Jun 2020:

      Just to add to the others’ answers, we don’t know how the first viruses formed. Some people think viruses arrived before or at the same time as cells, back when there was no life on Earth. I find this difficult because modern viruses all need cells to survive. There are two other ideas, that viruses either came from bits of DNA or RNA with genes that allowed them to make the protein coats that protect them, or from bacteria that lost so many functions that they stopped being able to produce more of themselves without a host cell. What’s crazy is that both of the last two ideas could be correct. What we think of as viruses could actually have several origins!

    • Photo: Melanie Krause

      Melanie Krause answered on 16 Jun 2020:

      Hi Lago! 🙂
      Thats a bit of a chicken and egg story ;).
      If you mean created in nature: We don’t actually know the original origin in nature for sure but they have been around since before humans existed. New viruses usually come from mutations of existing viruses that slow them to jump into a new host. So when there is a new virus that infects humans ii always comes from animals. And at this moment we definitely don’t know enough about animal viruses. As an example: HIV came from monkeys in Central Africa.

      If you mean created in the lab: I am a virologist myself and we don’t ‘make’ new viruses from scratch. What we sometimes do is that we change or delete one gene in an existing virus to study what that gene does in the original virus or we put a colour-tag on a gene to see where the protein that it makes ends up in an infected cell. That itself can already be quite tricky. We also study more harmless viruses for something called ‘gene therapy’ in which we try to use a virus that doesn’t harm the infected person to deliver genetic information of a protein that can help cure a disease in specific tissue but thats still in development.
      We definitely can’t create a new virus like movies often like to claim by fusing two viruses of different kinds together or by 3D printing them or any other means and thats probably for the better ;).

    • Photo: Aisling Ryan

      Aisling Ryan answered on 16 Jun 2020:

      Great question! Viruses, like any other cells, were created billions of years ago on Earth. Since then different cell types have grown into more complex things, like plants or animals, which may have trillions of cells (like humans). A virus is not complex and is only a single cell, but once it infects an animal or human it can use they animal/human cells to make more virus cells which is what causes an infection. We don’t know when the first ever virus formed in nature, but as long as humans have been around we know that viruses have been able to infect us.
      New viruses generally evolve from older viruses, and they make themselves better at something they do each time they evolve. One virus might become better at spreading, while another virus may become more camouflaged so that it’s harder to find, and another might become more deadly. But often a virus won’t be better at all of these things at once, so scientists have a chance to figure out what is going on and come up with the best strategy to keep us safe 🙂
      With COVID-19, this virus is very good and spreading and that is why our best strategy for the moment is social distancing and staying at home.

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