The development of smallpox vaccine led to the eradication of the disease in 1980 as declared by WHO. Now, the  variola virus that causes smallpox, only exists in two laboratories in the whole world for study purposes: US and Russia. The last case was reported in 1978, thanks to a selfless English doctor. In 1978, this 47- year doctor took substances from fresh cowpox lesions on a milkmaid called Sarah Nelms and injected a healthy 8 year old boy called james Phipps. As a result, he devloped a fever, dsicomfort in the armpit, cold and apetite loss. Two months later, he intentionally infected the same boy with small pox but no disease developed. Wallar! This doctor, Edwars Jenner, was a 13 year old oprhan when he first heard a milk maid say; "I shall never have smallpox for I have had Cowpox. I sahll never have an ugly pockmarked face." The following year, he sent a paper to the Royal Society in England but it was rejected. This didn't stop him. he went ahead and published a booklet suggesting that cowpox could offer protection from smallpox and distributed it, however it received a lot of critism from English people. he started collecting more cowpox samples and sent materials to anyone who cared to listen adn test the theory too.  Another scientists from America contacted him and proved that it was worked. This is how 

vaccination started, where cow is vacca in latina and cowpox being vaccinia. before this, people were scaping off lesions from people who haev conteacted the smallpox disease to make a powder which was later inhaled for protection against the disease. it was not as effective since a bigger population still got the disease, however, the procedure was reduced fatalities. the diseas was killing 3% of every smallpox patients. It usually started with a high fever, body and headaches followed by rusheds/lesions. recovered aptients often were left with ugly marks, disfiurement and blindness. By the time Dr. jenner dies in 1832, the vaccine was accepted widely after sending the vaccine to anyone who cared  using his resources. When the vaccination was going round, not everyone was able to afford it. This made him vaccinate poor people for free and had no intention of enriching himself. On his last days on earth, he withdrew from the public public eye after his wife and son died of tuberculosis. The hut he used for vaccination and the house he lived in is now a tourist attraction. iHis workl has since been developed and other vaccination have been made by using the same concept of using or cosntruction a less virultent vvirus of use of proteins that the virus produces to make an effective  vaccine for protection against disease.