Infectious diseases could now kill millions in a short period of time.

The Bubonic plague in 14th century Europe killed close to 200 million people.



Small pox in the 16th century wiped off around 90 per cent of the Native Americans.



A series of cholera outbreaks in 1800s killed millions around the world.

Our fight against the germs consists of the punch-counterpunch in the evolutionary boxing ring. A microbe evolves itself to colonise the human host, the humans then evolve antibodies against the particular microbe, and the cycle continues.

A major milestone in the fight against germs was the discovery of modern penicillin in 1928. Antibiotics to fight bacterial infections revolutionised medicine.

Now, diseases like cholera and plague could be effectively controlled with antibiotics.

This is why, when we look at the list of major pandemics, we find that the number of pandemics caused by bacteria declines in the 20th century.

In fact, each pandemic on the list since the 1918 Spanish flue is caused by a virus.