Who discovered 'vaccine' for the first time? Name two diseases which can be prevented by using vaccines.

Answer

A

Explanation

A 'vaccine' is a biological preparation that improves immunity to a particular diseases. Vaccine can be prophylactic or the apeutic.
An English physician, Edward Jenner (1749-1823) observed that people who sufffer cowpox(a mild disease) did not acquire smallpox, (a more severe disease). Jenner decided to test his observations about cowpox and smallpox.
He took some plus with a sterile needle from the cowpox rashes of an infected girl and injected it into scratches made in the skin of an uninfected boy, who sson got cowpox, A he recovered, Jenner injected the boy's arm with pus from the spots of a person suffering from smallpox. Luckily, the body did not get smallpox and Jenner's expermients was successful.
Thus, Jenner made the first vaccine against smallpox using the microbes of cowpox, a similar but less severse disease. The modern term 'vaccination' comes from the Latin words vacca which means cow and vaccinia meaning cowpox.
The second generation of vaccines was introduced inn 1880s by Louis Pasteur who developed vaccines for chicken pox, cholera and anthrax.