BOSTON (MarketWatch) -- Novartis AG plans to build a new vaccine plant in the United States that will use the latest technology to produce avian-flu vaccine more quickly for the U.S. market in case of a pandemic, according to Novartis Chief Executive Daniel Vasella. In an interview with MarketWatch late Wednesday, Vasella said that the plant, which will likely cost around $400 million, will tap new cell-based culturing technologies. The executive declined to speculate on how long it will take to bring the plant on line, saying only it could take "several years."