Alexander Fleming, a Scottish biologist, discovered penicillin in 1928. This discovery revolutionized the treatment of bacterial infections and saved countless lives.

The first vaccine developed was the smallpox vaccine, which was created by Edward Jenner in 1796. This vaccine prevented smallpox, a deadly disease that killed millions of people worldwide.

Louis Pasteur, a French chemist and microbiologist, developed the germ theory of disease in the 1860s. This theory revolutionized the understanding of infectious diseases and led to the development of new methods to prevent and treat them.

James Watson and Francis Crick, two British scientists, discovered the structure of DNA in 1953. This discovery was a major breakthrough in genetics and has had a profound impact on our understanding of life.

The first successful organ transplant was a kidney transplant performed by Joseph Murray and his team at the Peter Bent Brigham Hospital in Boston in 1954.

Smallpox was eradicated globally through a worldwide vaccination campaign led by the World Health Organization (WHO). The last case of smallpox was reported in 1977.

Selman Waksman, a Ukrainian-American microbiologist, discovered streptomycin in 1943, the first effective treatment for tuberculosis.

Jonas Salk, an American virologist, developed the first effective vaccine for polio in 1955. This vaccine significantly reduced the incidence of polio worldwide.

The first artificial joint replacement was a hip replacement performed by Sir John Charnley in 1960.

David Ho, an American physician-scientist, developed the first effective treatment for HIV/AIDS in 1996. This treatment, known as highly active antiretroviral therapy (HAART), has saved millions of lives.

The first successful gene therapy treatment was performed in 1990 to treat a young girl with ADA deficiency, a rare genetic disorder. The treatment involved inserting a healthy copy of the ADA gene into the girl's T cells.

Maurice Hilleman, an American virologist, developed the first effective vaccine for measles in 1963. This vaccine has significantly reduced the incidence of measles worldwide.

The first successful in vitro fertilization (IVF) procedure resulted in the birth of Louise Brown in 1978. This procedure was performed by Robert Edwards and Patrick Steptoe in England.

Charles Louis Alphonse Laveran, a French physician, discovered the parasite that causes malaria in 1880. This discovery led to the development of the first effective treatment for malaria, quinine.