According to the IPD Group a landmark study aimed at Egypt's hepatitis C pandemic, involving collaboration of the National Research Centre in Cairo and Medizone International, a US public company engaged in developing complementary therapies for hepatitis C, has been blocked by the New York State Department of Health (NYSDOH). Said a spokesman for Medizone: "the motives are clear. The NYSDOH has a history of strongly suppressing complementary therapies. Also, special interests are involved, potent economic forces fighting to keep the status quo on established pharmaceutical pipelines". The pandemic is believed to be caused, at least in part, by the failure of an earlier vaccination programme.