We may fear terrorist attacks but in truth humans have always had far more to fear from infections. In 1950 there were an estimated 50 million cases of smallpox worldwide, which killed 10 million people. At the end of WWI, Spanish flu proved deadlier than the war that had just eradicated nearly 20 million people. In 1980, before the measles vaccine was introduced, an estimated 2.6 million children died each year of this disease. Less than 100 years ago, child and infant death due to illness was a tragic event dreaded by every parent - from the most revered to the poorest.

Today, these diseases are seen not at all or only rarely, thanks to the development of antibiotics and vaccination. Vaccination, especially, has given 20th- and 21st-century parents a peace of mind their ancestors could only dream of.

The story of vaccination is rich with trial, error, sabotage and success. It's the tragedy of lives lost, the drama of competition and discovery, the culpability of botched testing, and the triumph of effective, lifelong immunity. Yet with the eradication in the first world of some of our deadliest diseases - and the fading memory of their awful consequences - complacency has set in. We forget the power of these diseases at our peril.

This is a book for everyone who fronts up to get their jabs and might want to be reminded why.