New Israeli mRNA vaccine may thwart deadly bacteria and bioterrorism threats

This breakthrough opens the door to developing mRNA vaccines for other dangerous bacteria, including those that are resistant to antibiotics.

By Pesach Benson, TPS

In a world-first breakthrough, Israeli scientists announced on Wednesday the development of an mRNA-based vaccine that protects against a deadly and drug-resistant bacterium — marking a major step forward in the fight against bacterial infections.

The vaccine, based on the same technology used for COVID-19 shots, offers full protection in animal models against Yersinia pestis, the bacterium that causes bubonic and pneumonic plague.

This is the first time researchers have proven that mRNA vaccines — which have until now only worked against viruses — can also be effective against bacteria.

“This is a true breakthrough,” said Prof. Dan Peer, Vice President for Research and Development at Tel Aviv University and one of the lead scientists on the project.

“We’ve shown that an mRNA vaccine can protect against a bacterial infection — something that wasn’t considered possible until now.”

The findings were recently published in the peer-reviewed Advanced Science journal.

Traditional mRNA vaccines, like those used during the COVID-19 pandemic, teach the body to fight viruses.

Viruses use human cells to multiply, so vaccines work by delivering genetic instructions (mRNA) that prompt cells to make harmless pieces of the virus. The immune system then learns to recognize and attack the real virus.

But bacteria are different. Bacteria are living, single-celled organisms. They can survive and reproduce on their own.

“Bacteria don’t need human cells to reproduce, and their proteins are very different from ours,” explained Dr. Uri Elia from the Israel Institute for Biological Research. “That’s why many experts believed mRNA vaccines wouldn’t work against bacterial infections.”

To overcome this, scientists from Tel Aviv University and the Israel Institute for Biological Research in Ness Ziona developed a method to trick human cells into making bacterial proteins in a way that still triggers a strong immune response.

The result: a working mRNA vaccine that teaches the body to recognize and destroy the plague-causing bacterium.

The team focused on pneumonic plague — the most dangerous form of the disease, which spreads from person to person through the air. After two vaccine doses, animal models showed complete protection: none of the vaccinated animals got sick.

“The success of this study opens the door to a whole new generation of mRNA vaccines against deadly bacteria,” said Peer.

Plague, which wiped out millions in the Middle Ages, still appears in places like Madagascar.

“There is no approved plague vaccine in Western countries,” said Dr. Elia. “Yersinia pestis is not only deadly and contagious — it could also be used as a bioterrorism weapon. That’s why it’s so important to have a vaccine ready.”

This breakthrough opens the door to developing mRNA vaccines for other dangerous bacteria, including those that are resistant to antibiotics, such as MRSA, tuberculosis, or Clostridium difficile.

The vaccine could also serve as a rapid countermeasure against biological threats because mRNA technology allows for faster design and production.

With this proof-of-concept, scientists now hope to apply the same mRNA approach to fight other bacteria — especially those that are resistant to antibiotics.