Having the posibility to change the history a bit, I would certainly change the fate of many people who died because of the worst killer plagues. I imagine that I am a Time Lord, and by the touch of my sonic screwdriver I can help all innocent people to overcome the disease or simple prevent it from happening.
First of all, I would prevent
SMALLPOX from spreading. This disease killed almost 300 million people worldwide in the 20th century. Smallpox is caused by either of two virus variants named Variola major and Variola minor. Its side-effects include the characteristic skin scars, but also blindness and infertility in male survivors.
MALARIA kills about 2 million people per year. It is one of the most common
infectious diseases and an enormous public-health problem. Malaria has
symptoms of anemia such as light headedness and shortness of breath, as well as other general symptoms like fever, chills, nausea,
flu-like illness, and in severe cases, coma and death. Despite efforts to reduce transmission and increase treatment, there has
been little change, because many cases occur in rural areas where people do not have access to hospitals or cannot afford health care.
AIDS killed 25 milion people worldwide. It was first recognized in 1981 and is one of the he most destructive epidemics in recorded history. It is a disease of the human immune system caused by the human immunodeficiency virus (HIV).
Apart from these diseases there are many others that killed many people such as : Cholere, Typhus, Spanish Flu, and Black Death.
Being able to help millions of people with my incredible sonic screwdriver and my brain, I would do everything ranging from
finding a vaccine, supporting whole comunities with needed drugs, and fulfilling dreams and desires of all patients. This would not require much effort from me.
It would be a pleasure.