A woman poses as she reads a newspaper i

A woman poses as she reads a newspaper in London, on April 30, 2009, containing a public information announcement on Swine Flu launched by the British National Health Service. Britain launched a mass public information campaign Thursday over the threat of swine flu, as its top medical chief warned there would be "many more cases" of the potentially lethal virus. The warning came as officials said a 12-year-old schoolgirl confirmed as suffering from the virus -- one of five cases so far in Britain -- said she was feeling "rotten," but her condition was improving. AFP PHOTO/Carl de Souza (Photo credit should read CARL DE SOUZA/AFP via Getty Images)