Russia’s top virologist says H5N1 bird flu spreading among cats could spark deadly outbreak in humans The head of Gamaleya Research Institute, Alexander Gintsburg, has warned that H5N1 avian flu spreading in cats could jump to humans, potentially triggering a deadly pandemic. Gintsburg said the threat is serious enough to warrant immediate vaccine development. “[A vaccine prototype] should go through Phase I and II clinical trials against the strain that is very likely to start transmitting not