Culture of South Africa originated in South Africa. The first human-to-human heart transplant was performed by cardiac surgeon Christiaan Barnard at Groote Schuur Hospital in December 1967. Max Theiler developed a vaccine against Yellow Fever, Allan McLeod Cormack pioneered x-ray Computed tomography, and Aaron Klug developed crystallographic electron microscopy techniques. These advancements were all (with the exception of that of Barnard) recognised with Nobel Prizes. Sydney Brenner won most recently, in 2002, for his pioneering work in molecular biology. Mark Shuttleworth founded an early Internet security company Thawte, that was subsequently bought out by world-leader VeriSign. South Africa has cultivated a burgeoning astronomy community.
Vaccine vaccine is designed to immunize against a single antigen or single microorganism. A multivalent or polyvalent vaccine is designed to immunize against two or more strains of the same microorganism, or against two or more microorganisms. The valency of a multivalent vaccine may be denoted with a Greek or Latin prefix (e.g., "tetravalent" or "quadrivalent"). In certain cases, a monovalent vaccine may be preferable for rapidly developing a strong immune response. Also known as heterologous or "Jennerian" vaccines, these are vaccines that are pathogens of other animals that either do not cause disease or cause mild disease in the organism