Smallpox is an infection caused by the variola virus.
For centuries, epidemics of smallpox affected people all over the globe, and the disease was often serious. But small pox vaccination discovered by an English doctor, Edward Jenner protected people from getting smallpox. This vaccine helped in eradicating small pox from the world.
Vaccination is the only effective weapon against the spread of smallpox.
People of all ages can contract this disease if exposed to the causative agent.