Broad Ebola vaccine research gains new urgency

1. What does the current Ebola outbreak mean for vaccine development?

“Development has clearly gained momentum. The current outbreak is caused by Bundibugyo, a rare ebolavirus species for which no approved vaccine is available. That makes the research even more urgent.

We started this CEPI-funded project with the aim of developing a vaccine that works as broadly as possible. That aim still stands. At the same time, the focus has now shifted to rapidly testing a new candidate vaccine that should protect against the Bundibugyo variant currently circulating in Central Africa.

This directly aligns with CEPI’s 100 Days Mission. This international ambition is to have a clinically testable vaccine available within 100 days of recognising a new viral threat. The current outbreak shows why it is important to have knowledge, technology and vaccine candidates ready before a crisis occurs.”

2. WUR is working with international partners on an ‘all-in-one’ vaccine against Ebola and Marburg. What is the idea behind this?

“Vaccine development for these kinds of viruses has so far mainly been reactive. A vaccine only becomes available when an outbreak is already almost over. With an ‘all-in-one vaccine’, we want to be better prepared.

The aim is a broadly effective vaccine that can be deployed quickly during outbreaks of different Ebola or Marburg viruses. A vaccin already exists against Zaire ebolavirus, but there are no licensed vaccines against Sudan ebolavirus, Marburg virus and Bundibugyo. That leaves an important vulnerability. Ideally, such a vaccine would also protect against variants we have not seen before. That is scientifically very challenging, but new AI tools are making it increasingly possible to develop promising vaccine candidates.

The international project in which WUR is involved should not only result in a candidate vaccine, but also in knowledge that can be used more quickly in future outbreaks. In this way, the research contributes to wider international preparedness for new viral threats.”

3. What is WUR’s role in this research?

“In Wageningen, we focus on producing (parts of) Ebola virus proteins that trigger a strong immune response. These proteins should help the immune system recognise the virus to, hopefully, protect against infection.

For this protein production, we use insect cells. This is a technology for which WUR has considerable expertise. Within the project, WUR is making several vaccine candidates. Other partners then test, among other things, their safety and immunogenicity: the ability of a vaccine to activate the immune system. We are working in an international group of scientists, including the Danish company AdaptVac and the Radboudumc. We previously worked with these partners on a COVID-19 vaccine. We are now using the technology developed during the pandemic again.”

4. How far is this candidate vaccine from application?

“Some catching up was needed, because relatively little research had been done worldwide on Bundibugyo. Fortunately, the first vaccine candidates have now been designed and animal studies have started.

How quickly the next steps can be taken depends on the results of those studies and on the cooperation between the partners involved. That cooperation is crucial. CEPI plays an important role in this, because the organisation helps accelerate the research and connect it internationally.

For an ongoing outbreak, speed is important, but careful assessment remains a priority. A candidate vaccine can only be taken further if studies show that it is safe enough and triggers the desired immune response.”

5. Is there reason to be concerned about these kinds of viruses?

“Virus outbreaks almost always come unexpectedly. They can also have major consequences for society. That is why it is important to maintain a high level of knowledge and technological expertise.

The aim is to develop a collection of vaccines far enough that they can be deployed in time during a new outbreak. This could make it possible to slow down further spread more quickly. Preparation is essential, especially for rare but dangerous viruses. We are pleased that WUR can contribute to this.”