A child born in the 15th century had a one-in-three chance of dying before the age of 15 from causes such as pneumonia, whooping cough, dysentery, smallpox or flu. Even as late as the First World War, soldiers had a greater chance of dying from influenza than in combat. Vaccines have led to the eradication of deadly infections such as smallpox and today, according to the World Health Organization, they help prevent up to three million deaths a year. But a lot more needs to be done to find effective vaccines against diseases that impact the planet’s poorest most, such as malaria, tuberculosis and HIV.
Early records show smallpox was found in Egypt around the third century BCE. Among the deadliest diseases, smallpox killed about a third of the people it infected. Vaccination in a crude form existed in China and India a thousand years ago. A process known as ‘variolation’ involved grinding up smallpox scabs and blowing the material into the skin or the nostril of a healthy person. They would get a mild form of the disease but become less likely to die from it. This practice spread across Africa and the Middle East before reaching Europe in the 18th century.
