The TWiV team explains how infectious horsepox virus – likely the ancestor of smallpox vaccines – was recovered from chemically synthesized DNA fragments.
The TWiV team reviews the discovery of old vials of smallpox virus at NIH, anthrax and influenza mishaps at CDC, the baby who was not cured of HIV, Cambridge Working Group, and sacking of NSABB members.
The Twivsters discuss how reverse transcriptase encoded in the human genome might produce DNA copies of RNA viruses in infected cells.