Ebola outbreak: When will a vaccine be developed for the new strain?

What do we know about the new strain? How deadly is it?

The Bundibugyo strain of Ebola is a distinct species within the Ebola virus family. It differs from the Zaire Ebola virus strain, which caused the large 2014-2016 West Africa outbreak, Krutika Kuppalli, associate professor at the Infectious Diseases and School of Public Health at UT Southwestern Medical Center in Dallas, Texas, told Al Jazeera.

“While Bundibugyo has caused fewer outbreaks historically, it is still a very serious pathogen. Prior outbreaks have had case fatality rates ranging from approximately 30-50 percent, and the current outbreak is particularly concerning because there are currently no licensed vaccines or specific therapeutics for Bundibugyo virus disease,” she said.

Kuppalli added that ongoing conflicts in the region, which have been accompanied by vast population displacement, weak surveillance systems and delayed detection, will make the latest outbreak more challenging to contain.

“Early cases may have been missed in part because many front-line diagnostic platforms were optimised for Zaire Ebola virus and do not reliably detect Bundibugyo virus,” she said.

“We are now seeing this strain of the virus spread into urban and cross-border settings, which raises concern about amplification if containment measures are not rapidly strengthened,” she warned.

Will there be a vaccine?

There is currently no approved vaccine for this strain of the Ebola virus.

A vaccine named Ervebo, ⁠manufactured by Merck, which was used against the Zaire strain of Ebola, has been shown to provide some protection against ⁠Bundibugyo in animal studies.

Kuppalli from the UT Southwestern Medical Center explained that vaccine development timelines are difficult to predict.

“The scientific community is not starting from zero as there is already extensive knowledge from prior Ebola vaccine work, including viral vector and mRNA platforms that could potentially be adapted for Bundibugyo virus,” she said.

“However, moving from candidate design to clinical trials, manufacturing, regulatory review, and deployment still takes time, particularly during an active outbreak in resource-limited settings,” she added.

She noted that organisations such as CEPI (the Coalition for Epidemic Preparedness Innovations) have already recognised the need for broader “multivalent” filovirus vaccines that could protect against multiple Ebola species, including viruses that have not yet emerged widely in humans.

“CEPI has recently funded research specifically focused on broadly protective filovirus vaccines and rapid-response vaccine platforms. Their work reflects a growing recognition that relying on species-specific vaccines leaves the world vulnerable when a different Ebola species emerges,” she said.

Until a vaccine to prevent the latest strain is developed, a WHO official said on Tuesday that medical supplies, including personal protective equipment (PPE) ⁠to prevent Ebola, were due to arrive in ⁠the DRC.

“We have sent 12 tonnes of supply. An additional six are arriving today. These include personal protective equipment for ⁠front-line health workers [and] samples,” Anne Ancia, WHO representative in the Democratic Republic of ⁠the Congo’s Ituri province, told media.

Jean-Jacques Muyembe, a virus expert at the DRC’s National Institute of Biomedical Research, told reporters the country was also expecting shipments of an experimental vaccine for different types of Ebola from the United States and the United Kingdom.

How are other countries responding?

Many countries have raised concerns about the latest Ebola virus outbreak and some, including Bahrain, have suspended the entry of foreign travellers arriving from South Sudan, the DRC and Uganda, for 30 days due to the outbreak.

Rwanda has also closed its borders with the DRC.

The US has implemented a 30-day temporary entry restriction for non-US citizens and non-permanent residents who have travelled to the DRC, Uganda or South Sudan within the prior 21 days.

Meanwhile, governments across Asia have begun introducing border screening and bolstering quarantine preparedness.

Will there be a similar response to the COVID outbreak?

There is not the same urgency about developing a vaccine for Ebola as there was during the COVID-19 pandemic, Kuppalli said.

“COVID-19 vaccine development moved at unprecedented speed because the outbreak affected wealthy countries and rapidly disrupted the global economy,” she explained.

“African outbreaks have historically not generated the same urgency, financing, manufacturing investment or political attention despite causing devastating local consequences,” she said.

Kuppalli noted that Ebola vaccine development following the 2014 outbreak accelerated only after thousands of people had already died in West Africa.

“I do think there has been progress since 2014. Global partnerships involving WHO, CEPI, GAVI [the vaccine alliance], African scientists, regulators and research institutions are much stronger than they once were,” she said.

“The challenge now is ensuring sustained investment before crises become global threats, rather than only responding once outbreaks reach high-income countries. This outbreak underscores why equitable investment in epidemic preparedness and vaccine research matters not just for Africa, but for global health security overall,” she added.