Merck (MSD) announced this week that it would be donating approximately 50,000 doses of its investigational vaccine for the Sudan Ebola virus (SUDV) to the International AIDS Vaccine Initiative (IAVI).
The doses will be made from drug substance previously manufactured by Merck, and support the World Health Organizations’ (WHO) response to the recent outbreak declared in Uganda. As of late September of this year, the WHO reported 44 possible deaths in Uganda, officially declaring it the country’s first Ebola disease outbreak caused by the SUDV since 2012. Before this one, the country had reported four SVD outbreaks, in 2000, 2011, and two in 2012.
The vials of investigational Sudan ebolavirus vaccine use a replication-competent, live, attenuated recombinant vesicular stomatitis virus (rVSV) vaccine construct similar to that used for Ervebo, the company’s vaccine approved for the prevention of disease caused by Zaire ebolavirus. Ervebo is approved in the United States, EU, UK, Switzerland, and ten African countries.
The public was first made aware of the extra doses by Science just last week, and initially, Merck told Science via email earlier this month that indeed the vaccine had been made but that vials of it had expired and were destroyed in 2021. Following further inquiry, company reps acknowledged that Merck did retain bulk quantities of the frozen Ebola vaccine drug substance and arranged an interview with the reporter. According to Science, Merck made the product in 2015 and 2016, froze it in bulk form and never tested it on people.