• Question: How many types of viruses are there?

    Asked by anon-266969 to Victoria, Suzan on 6 Nov 2020.
    • Photo: Victoria Cox

      Victoria Cox answered on 6 Nov 2020:

      Hi there! It depends what you mean by type. Type could mean ‘what they can infect’ – there are different viruses which infect humans, animals or plants. It could mean ‘how they are spread’ – there are viruses which are spread in the air (for example when someone infected coughs near you) or through blood (for example if a mosquito carrying the virus bites a human and it passes from their saliva into the human’s blood) and many other ways. Type could also mean ‘how they behave in our bodies,’ for example some viruses cause a lot of damage quickly and the person is ill but then recovers (like a cold or flu virus) or some viruses stay in the body a long time (like HIV). There are probably millions of viruses out there (we don’t know all of them, and more are being discovered all the time), but not all of them are harmful and not all of them can infect humans.

    • Photo: Suzan Kors

      Suzan Kors answered on 7 Nov 2020:

      Hi! I agree with Victoria – there are many different types of viruses, and we don’t even know them all, which means we can keep researching them. I don’t research viruses myself but there are people in my lab who are looking at viruses in the ocean, which I think is pretty cool! I once read that the total number of viruses on the planet is more than the stars in the universe – which I find a really interesting fact.

Comments

  • Photo: Thomas

    Thomas commented on :

    A lot, but it’s very difficult to say exactly how many.

    Most scientists would say a virus was a different strain (type) based on its genetic information- either DNA or a similar thing called RNA. Where this gets tricky is that viruses get an awful lot of mutations, changing the RNA/DNA. How many mutations it takes a virus to become a different virus is very difficult to say and can be different depending on the virus!