smallpox

In 1721, London was in the grips of a deadly smallpox epidemic. One woman learned how to stop it, but her solution sowed political division.

Labs are churning out more and more synthetic DNA for scientists who want to use it to reprogram cells. Some say the technology has outpaced government safety guidelines put in place a decade ago.

That's one of the themes in the new book Between Hope and Fear: A History of Vaccines and Human Immunity.

U.S. regulators Friday approved the first treatment for smallpox — a deadly disease that was wiped out four decades ago — in case the virus is used in a…