Diary
Hugh Pennington: Smallpox Scares, 5 September 2002
“... from their use are far more common and more serious than from any other vaccine. Their origins are unknown: genetic fingerprinting has shown that they did not come from Jenner’s cowpox vaccine and records of their lineage fade into complete obscurity in the 19th century. There is a story that one strain came from a soldier during the Franco-Prussian ... ”