Smallpox is one of the deadliest diseases known to mankind, responsible for the death of millions of people worldwide. It is caused by a virus, and until recently, there was no cure. The virus is highly contagious and is spread through contact with an infected person or object. Symptoms of smallpox include fever, chills, and a rash of small red bumps that become blisters full of pus and eventually scab over. Complications from the infection can include blindness, disability, and even death. In the 1900s, the World Health Organization began a successful campaign to eradicate smallpox, making it the first disease to be eradicated through vaccination. This campaign involved mass inoculations and testing of people around the world, as well as quarantine and surveillance methods to contain spread of the virus. Today, smallpox is considered eradicated, however, there is still concern that the virus could be used as a biological weapon. Vaccines are still available for those at risk, but no new cases of the disease have been reported in over 30 years. The success of the global eradication of smallpox is a testament to the power of science and medicine, and it serves as a reminder of the importance of public health measures in controlling and ultimately eradicating other infectious diseases.