As positive news from Uganda emerges that no new cases of Ebola have been identified concerns about the future of anticipated vaccine trials in the region. Writing in Science in December 2022 Jon Cohen contrasted the “uplifting news” of the possible containment of the virus with “formidable hurdles” that the trials are continuing to face.
MoH case count
Dr Diana Atwine, Permanent Secretary of the Uganda Ministry of Health, shared an image on Twitter that detailed the official numbers. Her caption stated that she was “happy to announce” that the last Ebola patient had been discharged.

Image from @DianaAtwine on Twitter
“We are sorry for those who predicted doom for Uganda. God has seen us through this epidemic.”
Dr Atwine also emphasised that the Ministry was following up with the “remaining contacts” for the appropriate 21 days. According to Cohen, these contacts are “dwindling fast”, with only a few hundred remaining – roughly 20 per case. The outbreak will be declared over 42 days after the final case.
What does this mean for vaccines?
As Cohen identifies, this is a great sign for Uganda and its “aggressive containment efforts”. However, it does confuse efforts to trial vaccines in situ, which have already been complicated by due process. After generating $9 million in funding and jumping through permit and supply hoops, researchers are now unsure about the future of the trials.
A few weeks ago, we explored the suggestion that Merck had found “potentially game changing” frozen doses of an experimental vaccine. Shortly after that, the WHO, Gavi, and CEPI, announced a plan to “accelerate research” and promote vaccine investigation in Uganda.
Clearly no one wishes for more patients to suffer the terrible effects of Ebola, and some researchers are suggesting that vaccine trials can go ahead in healthcare workers anyway. Furthermore, we still have lessons to learn from this outbreak, which highlighted the need for a secure and confident response system. Seth Berkley, CEO of Gavi suggests that to “crack” the problem we need to stockpile vaccines in preparation. This is costly and can be wasteful, but it would potentially save lives.
Caution ahead
Despite the positive news from Uganda, WHO’s Executive Director of the Emergencies Programme, warns that we have “significant faps” in transmission tracing, and must proceed with the high level of caution already demonstrated by the health authorities in Uganda.
“Ebola always has a sting in its tail.”
For more on current and future vaccine approaches to Ebola come to the World Vaccine Congress in Washington 2023.