Researchers in China have developed an experimental mRNA vaccine that could provide broad and long-lasting protection against multiple deadly strains of Ebola viruses, including the Bundibugyo strain responsible for recent outbreaks in the Democratic Republic of Congo and Uganda.

Ebola virus disease is a severe hemorrhagic fever that can cause high fever, vomiting, internal bleeding, organ failure, and death in roughly half of infected patients. The virus spreads through direct contact with infected blood or bodily fluids.

Currently, available Ebola vaccines mainly target the Zaire ebolavirus strain, leaving limited protection against other dangerous variants. Scientists say a vaccine capable of defending against several Ebola species at once is urgently needed.

To address this problem, Chinese researchers created a multivalent mRNA vaccine known as [GPs+NP]@LNP, using technology similar to that employed in COVID-19 vaccines. Instead of containing weakened viruses, the vaccine delivers genetic instructions that help the immune system recognize proteins from several Ebola-related viruses, including Ebola, Sudan, and Bundibugyo strains.

The vaccine combines three viral surface glycoproteins, which help the virus attach to human cells, together with a nucleoprotein that is highly similar across different Ebola strains. According to researchers, this design aims to stimulate both antibody production and strong cellular immune responses capable of destroying infected cells.

The vaccine was tested in mice exposed to Ebola and Bundibugyo viruses, as well as hamsters infected with the Sudan virus. Scientists reported highly encouraging results.

Mice vaccinated against Ebola showed complete survival and effectively cleared the virus from the bloodstream and major organs such as the liver and spleen. The vaccine also significantly reduced viral levels in animals exposed to the Bundibugyo strain. Hamsters infected with the Sudan virus maintained stable body weight and eliminated detectable virus from their blood.

Researchers said one of the most notable findings was the durability of the immune protection, which remained effective for approximately 17 months after vaccination in mice.

The scientists described the vaccine as a promising candidate for the next generation of broad-spectrum Ebola vaccines. However, they emphasized that the research is still at an early stage and must undergo further testing in larger animal models, including non-human primates, before human clinical trials can begin.