A confirmed case of bird flu in China has confirmed that the threat of human-to-human contagion is still largely limited to the blood relatives of those infected. In an important case for vaccine developers, the man recovered after he was given plasma drawn from a woman who had received an experimental bird flu vaccine that had been made from whole, killed H5N1. The vaccine was made by Sinovac from a 2004 Vietnamese strain of the disease. If researchers can show that the recovery was linked to the vaccine, the whole virus vaccine could prove a key to spurring immunity to a range of possible mutations of H5N1. Report