Dr. Norman Swan explains the process of zoonoses and the kinds of viruses that have been created through this process. #InvisibleWars
Dr. Norman Swan uncovers the gripping stories and life-changing scientific breakthroughs from our past clashes with deadly respiratory viruses.
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Viruses that originate in animals are known as zoonoses. Scientists are concerned about the alarming rise of lethal pathogens jumping over to humans over the last 50 years.
So a zoonotic disease is essentially a disease that spilled over from one species into another. Sometimes they can then spread on to other humans. And that's when you can have a pandemic situation.
Influenza, Ebola, SARS, and COVID-19 are just some of the deadly diseases which originate in animals. Passed to humans through a process called spillover. In order for an animal virus to infect a human, its protein keys will often change to gain entry. This happens through mutation and viruses mutate much faster than we do.
So when we replicate, we have lots of checks and balances and repair mechanisms. It takes 15 years to become fertile, and then nine months in pregnancy, so you don't really want to have a mistake, because you've only got a few shots on goal. Viruses are different. They can replicate in hours, and they can make millions and millions of copies of themselves. So they're actually quite error-prone. They make zillions of mistakes. This means that that's an advantage for evolution because when they're making so many changes so quickly, they can adapt. They're more versatile and more able to change quickly, and sometimes even jump from one animal to another animal.
There is a risk of another pandemic at all times because there is a reservoir of viruses out there in nature to which we are not immune.
Decades of scientific research have uncovered a vast number of viral threats lurking within the environment.
There's still a lot to learn about potentially hostile viruses in the natural world. But as we gain more intelligence about these enemies lying in wait, we can develop sophisticated tools to defend ourselves. You see, when a virus emerges, the best way to win these battles is to arm our immune systems with a vaccine. Immunisation has won some stunning victories. But viruses are agile opponents, which continue to challenge even our best weapons of defence.