The Democratic Republic of Congo (DRC) is currently facing a significant Ebola outbreak, marking the third-largest on record. This outbreak is caused by the Bundibugyo strain of the virus, which has previously been linked to outbreaks in 2007 and 2012. Despite the recurring nature of these outbreaks, there is still no approved vaccine specifically targeting this strain.

Vaccine Development Challenges

The Zaire strain of Ebola has been the focus of most vaccine development efforts, leading to the creation of the Ervebo vaccine, approved by the US FDA in 2019. However, its effectiveness against the Bundibugyo strain remains uncertain. Dr. Anne Ancia from the World Health Organization (WHO) notes that the Zaire-targeted vaccine’s cross-protection for Bundibugyo is limited, raising concerns about its deployment in the current outbreak.

Research led by Dr. Thomas Geisbert at the University of Texas Medical Branch has shown some protection in monkeys using a similar vaccine, but larger studies are needed to confirm its efficacy and safety in humans. The potential risk of using a vaccine that might divert the immune response is a significant concern.

Promising Developments

Efforts are underway to develop a vaccine specifically targeting the Bundibugyo strain. An experimental vaccine using vesicular stomatitis virus to deliver Ebola proteins has shown promising results in nonhuman primates, providing complete protection. However, clinical-grade materials for human trials are still months away.

Another approach involves using technology from the Oxford University/AstraZeneca Covid-19 vaccine, which could be ready for trials within a few months. Despite the potential for rapid development, this vaccine has less supporting data and carries a small risk of blood clots.

Therapeutic Options

In addition to vaccines, therapeutic options are being explored. Broad-spectrum antiviral drugs like remdesivir and monoclonal antibody cocktails such as MBP134 show potential against multiple Ebola strains, including Bundibugyo. However, logistical challenges in administering these treatments in remote areas like Ituri province, where the outbreak is centered, remain a hurdle.

As the world has seen with past health emergencies, expedited vaccine development is possible. The current focus on Bundibugyo-specific vaccines and therapeutics offers hope for controlling this outbreak and preventing future ones.

Original reporting: KTVZ (Central Oregon) — read the source article.