Merck, Wellcome join global health group to develop Ebola vaccine for trials

• The Congo outbreak has infected 3,360 people and killed 1,487 as of July 29, with cases rising at 'worrying speed' according to CEPI
• The vaccine uses the same rVSV platform as Merck's approved Ervebo vaccine for the Zaire Ebola strain and was identified by WHO as the most promising candidate in May
• CEPI is simultaneously funding other vaccine candidates including an $8.6 million investment in Oxford's ChAdOx1-based vaccine and up to $50 million for another Bundibugyo vaccine

Summary: Merck-Wellcome Partnership to Develop Bundibugyo Ebola Vaccine

Key Development:

Hilleman Laboratories, a Singapore-based joint venture between Merck and global charity Wellcome, is manufacturing an experimental vaccine against the rare Bundibugyo Ebola strain currently spreading in the Democratic Republic of Congo. The Coalition for Epidemic Preparedness Innovations (CEPI) is backing the effort with up to $8.5 million in funding.

Outbreak Severity:

As of July 29, 2026, the eastern Congo outbreak has infected 3,360 people and killed 1,487. No vaccines or treatments are currently approved for Bundibugyo Ebola, making this a humanitarian crisis requiring urgent response.

Vaccine Technology:

The single-dose vaccine, developed by the International AIDS Vaccine Initiative (IAVI), uses the same recombinant vesicular stomatitis virus (rVSV) platform as Merck's approved Ervebo vaccine for the Zaire Ebola strain. The WHO identified it as the most promising candidate in May. Clinical testing doses could be ready by end of 2026.

Manufacturing Plan:

Hilleman Labs will produce tens of thousands of doses for early-stage trials using IAVI starting material, with Merck providing technical expertise. If trials succeed, partners plan to transfer technology to a large-scale manufacturer.

Additional Efforts:

CEPI is also funding other candidates, including $8.6 million for a University of Oxford vaccine (using ChAdOx1 COVID technology) manufactured by Serum Institute of India, and $50 million for another Bundibugyo vaccine. The WHO is considering trials of treatments from Mapp Biopharmaceuticals, Gilead Sciences, and Regeneron.