Question: How do viruses develop new strains of itself?#
Nuru Noor answered on 19 Mar 2020:
Just like human cells are constantly replicating – sometimes spelling mistake occur when copying our genes – this might do nothing or sometimes lead to medical conditions like cancer.
In the same way – viruses are constantly replicating and the genes that can up the genetics of viruses can change and so new strains of virus can form
Robyn Kiy answered on 19 Mar 2020:
As Nuru has said, mistakes that occur during the replication of viruses can lead to altered genetics, and therefore new strains of the virus. This process in biology is known as ‘mutation’!
M S answered on 19 Mar 2020:
So theres 2 main concepts. Antigenic shift and antigenic drift. So lets split up the words first.
An antigen is basically the proteins on the outside of a virus. So whenever you see a picture of a virus you see these things sticking outside of the virus. Like spikes. These are antigens.
Basically they can be summarised as this.
– Antigenic drift: So imagine a drift of wind. Thats what antigenic drift is. Its when a virus makes small changes over time. Each time it replicates it makes small changes and over time changes these antigens on its surface
– Antigenic shift. Like the name suggests its a big shift! not as calm as a drift. So what you have here is much different. Its when different types of the same virus mix together. It happens much more quickly and the changes on the surface of the protein make a new type of virus.
This happened with swine flu a few years ago. The virus from pigs, birds and humans merged making a new type of virus.
Look at this for help!
Nathan Kindred answered on 19 Mar 2020:
Excellent answers here! Just to add, developing new strains allows viruses to adapt to different environmental conditions and compete with other viruses and bacteria 🙂
Ioana Grigoras answered on 20 Mar 2020:
I think the previous answers are great and I don’t really have anything else to add.
Sarah Clarke answered on 20 Mar 2020:
Like others have said, the virus spends its time making lots and lots of copies of itself. However sometimes some of the copies will have a mistake in them which makes a slightly different version of the virus. Over time the virus can look very different to how it did at the start (antigenic drift) – you can think of it a bit like a game of Chinese whispers were the message at the end sounds very different to the message at the start. Sometimes the virus will make a big change when it replicates and this can also make it look different (antigenic shift).
Sophie Arthur answered on 20 Mar 2020:
There are fab answers already here. Nothing to add from me