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Why Do Viruses Kill?

Scientific issues. In the wake of dire warnings about new flu variant H1N1, Horizon follows the researchers trying to unravel viruses' secrets to understand when and why they kill.

Just months ago, the world stood in fear of an emerging new disease that threatened to kill millions. A new flu variant H1N1 had arrived. In the UK alone, 65,000 deaths were predicted. Yet to date, these dire warnings have not materialised.

If this latest pandemic has taught anything, it is just how little is understood about the invisible world of viruses. But that has not stopped scientists trying.

Horizon follows the leading researchers from across the world, who are attempting to unravel the many secrets of viruses to understand when and why they kill.

1 hour


Timings (where shown) are from the start of the programme in hours and minutes

  • Why do Viruses Kill?

    An introduction to how and why viruses exist, and what the experts know about them.

    Duration: 01:54

  • Swine Flu

    A look at the swine flu pandemic of last year and how scientists’ predictions weren’t as bad as they first thought.

    Duration: 04:04

  • What is a Virus and How Does it Work?

    Several scientists discuss what viruses look like and what they are capable of. One scientist, Curtis Suttle, even demonstrates that there is no escaping them.

    Duration: 08:01

  • The Origins of the Virus

    Dr Mark Young explains just how long viruses have been on this earth and how they’ve made a significant contribution towards the evolution of different life-forms.

    Duration: 05:39

  • How do Viruses Spread?

    Different techniques are adopted in order for a virus to infect a larger number of organisms, and these effects can damage and destroy in a variety of ways.

    Duration: 08:06

  • Viruses Between Species

    Dr Anne Rimoin is on the hunt for the next disease that will jump the species barrier, monkey pox. However catching the disease is unavoidable for some.

    Duration: 07:23

  • Vaccines

    The smallpox virus that killed so many has now been eradicated, but how? And could vaccines be created for other viruses?

    Duration: 04:39

  • HIV

    This particular virus mutates at such a rate that trying to combat it is extremely difficult. One woman discusses how she had to make the toughest decision of her life when she found out she had HIV.

    Duration: 06:13

  • Re-Assortment

    Different viruses can mix up their genes to create a new strain of virus, such as swine flu. Although this creates a new challenge, scientists believe viruses don’t actually want to kill humans.

    Duration: 04:13

  • The Next Pandemic

    Dr Eckhart Wimmer had the idea of creating a virus in order to understand more about them. However this means doing something that has proved very controversial.

    Duration: 08:26