Maria Odette Santos Ferreira (4 June 1925 – 7 October 2018) was a Portuguese professor of microbiology who played an important role in research on HIV, through the identification of the HIV-2 virus in association with the Pasteur Institute of Paris.

She was soon invited to spend a three-month internship with the Pasteur Institute, leaving her husband, also a pharmacist, and two daughters behind in Lisbon to go to Paris.

On completing the internship, where she had been made aware of techniques for identifying the AIDS virus, she started a doctorate on the topic of hospital infections, receiving a PhD from Paris-Sud University in 1977.

After the Carnation Revolution (25 April 1974), in which the authoritarian Estado Novo government was overthrown, she had several different roles in the reorganization of the University of Lisbon, as a member of the Board of Directors and of the Pedagogical Council.

[1][2] In the 1980s, Ferreira worked continuously with the Pasteur Institute, where she developed detection techniques for the HIV-1 lymphadenopathy-associated virus (LAV), one of the etiological agents of HIV, and made the first diagnoses of cases of AIDS in Portugal, including that of the famous Portuguese singer António Variações.

The research Ferreira carried out at the Pasteur Institute in the following two weeks, together with Nobel Prize winners Françoise Barré-Sinoussi and Luc Montagnier, culminated in the identification of a new type of AIDS virus, HIV-2, and paved the way for comparative studies between HIV-1 and HIV-2.

Her discovery of HIV-2, its epidemiology and diagnosis, made in collaboration with the Pasteur Institute and with José Luis Champalimaud from the Egas Moniz Hospital, came to revolutionize the world of serological diagnosis and helped the Retrovirus and Associated Infections Unit (CPM-URIA) at the University of Lisbon to expand and concentrate important lines of research in the area of retroviruses.

[4] She promoted several home-support services coordinated by the Solidarity Project of the Santa Casa da Misericórdia de Lisboa, and the construction of a residence to support AIDS patients through provision of palliative care (Residência Madre Teresa de Calcutá).

In Portugal, in 1988, she was made a Commander of the Military Order of Saint James of the Sword (Portuguese: Ordem Militar de Sant'Iago da Espada).