 In 1981, Mathé became a founding member of the World Cultural Council.From 1990 to 2008, Mathé worked as a consultant at the Paris Swiss Hospital, at the Rome European Hospital, at the Sofia Oncological Hospital, at the Belgrade Civil Hospital and at the Hôpital Paul-Brousse.In the early 1990s, conscious of the immunological nature of HIV/AIDS, Mathé applied immunotherapy to a dozen patients.