Themis has a pipeline of vaccine candidates and immune modulatory therapies developed using its measles virus vector platform. Originally developed by scientists at the Institut Pasteur, the technology was exclusively licensed to Themis in 2010.

In response to COVID-19, Themis formed a consortium to develop a SARS-CoV-2 vaccine in collaboration with Institut Pasteur and the Center for Vaccine Research at the University of Pittsburgh. Funding has been provided by the Coalition for Epidemic Preparedness Innovations (CEPI).

The acquisition is expected to advance the development of Themis' vaccine candidate, which is currently in preclinical development, and scheduled for clinical trials later in 2020. Under the agreement, Merck will acquire all outstanding shares of Themis in exchange for an undisclosed cash payment. Upon completion of the deal Themis will become a wholly owned subsidiary of Merck.

Institut Pasteur, CEPI, and Merck have entered into a memorandum of understanding whereby the organizations agree to address the COVID-19 pandemic by developing, manufacturing, and distributing the vaccine on a global basis and with pricing that makes the vaccine both available around the world and accessible to those who need it.