Israeli scientists have developed the world’s first mRNA plague vaccine targeting Yersinia pestis, the bacterium responsible for plague. The vaccine has shown strong preclinical protection in mice, offering a promising step forward in bacterial infection prevention
Plague: An Ancient but Persistent Threat
Plague, caused by the bacterium Yersinia pestis, was responsible for the infamous “Black Death” in the Middle Ages, claiming tens of millions of lives. Although modern antibiotics can effectively treat the disease, mortality rates still range from 60%–100% if treatment is not initiated within 24 hours of infection. Rising concerns about antibiotic-resistant strains have further highlighted the urgent need for new preventive tools.
mRNA Technology Crosses Into Bacterial Diseases
Previous plague vaccine candidates faced significant limitations, including weak durability of immune protection, low production efficiency, and safety issues. The new mRNA-based vaccine developed by the Israeli team encodes the genetic sequences of two key Y. pestis antigens—F1 and V proteins—into mRNA molecules, delivered via lipid nanoparticles. Once injected, the vaccine trains the immune system to mount a strong antibody and T-cell response.
Preclinical Success in Mice
In mouse experiments, the vaccine showed striking efficacy:
1.Nearly 100% survival in vaccinated mice after exposure to lethal doses of Y. pestis.
2.Complete mortality in the unvaccinated control group.
Researchers emphasize this is the first proof-of-concept that mRNA technology can protect against bacterial infections, as previous applications had been almost exclusively focused on viral diseases.
A spokesperson from the Israel Institute for Biological Research described the breakthrough as a potential game-changer not only for plague prevention but also for addressing other antibiotic-resistant bacterial threats.
Strategic and Public Health Implications
The vaccine is currently in the preclinical stage and has not yet been tested in humans. Although global plague incidence has significantly declined, sporadic outbreaks still occur in parts of Africa and Central Asia. Moreover, Y. pestis is classified as a potential bioterrorism agent, giving this research not only public health importance but also strategic relevance.
