A team of American scientists has developed a messenger RNA (mRNA) vaccine against the bacterium that causes Lyme disease, News.ro reports.

Preclinical studies show that the experimental vaccine has shown promising results in reducing the number of cases of Lyme disease.

An experimental mRNA vaccine provided protection in preclinical models against infection with Borrelia burgdorferi, the bacterium that causes Lyme disease, according to new research at the University of Pennsylvania Perelman School of Medicine.

Results obtained in animal models suggest that the vaccine prevents the development of Lyme disease and may be a powerful tool to reduce the number of cases of the disease.

How does Lyme disease manifest itself?

The bacteria that cause Lyme disease are transmitted to humans through the bites of infected ticks and can cause fever, headache, fatigue, and a rash.

If left untreated, the infection can spread to the joints, heart, and nervous system.

Most cases of Lyme disease can be successfully treated with a few weeks of antibiotics, but some people develop post-treatment Lyme disease syndrome (PTLDS), which can cause long-term symptoms such as severe joint pain and neurocognitive problems.

Although there are Lyme disease vaccines for dogs, none are currently approved for routine use in humans.

What researchers say about the vaccine they developed

“Bacteria are more complex organisms than viruses, so it may be more difficult to develop effective vaccines against them,” said lead author Norbert Pardee, associate professor of microbiology.

“We were able to identify an mRNA vaccine target that showed promising results for preventing B. burgdorferi infection in animal models,” he said. The vaccine, recently described in the journal Cell Press, uses the same messenger ribonucleic acid (mRNA) technology used in Pfizer and Moderna’s SARS-CoV-2 vaccines, which were first developed at Penn.

Together with mRNA vaccine pioneer Dr. Drew Weissman, director of the Pennsylvania Vaccine Research Center, Prof. Pardee and his lab identified one of the B. burgdorferi proteins that elicits a strong immune response, called outer surface protein A (OspA).

OspA is a conserved protein in many strains of B. burgdorferi, making it an ideal target for preventing the progression of an initial infection with this bacterium to Lyme disease.

How the messenger RNA vaccine works

Tests in animal models showed that an mRNA vaccine targeting OspA induced, after a single vaccination, a strong antigen-specific antibody and T-cell response that could protect against B. burgdorferi infection.

In addition, the vaccine elicited a strong memory B-cell response, which can be activated much later to help prevent B. burgdorferi infection long after vaccine administration.

According to Penn experts, the number of cases of Lyme disease has suddenly increased in the United States, which has led to the need to develop a vaccine to protect the population from infection.

“The mRNA technology has great promise for use in the development of a vaccine that could prevent Lyme disease and the subsequent development of the debilitating symptoms of PTLDS,” the Penn scientists said.

The study was funded by the US National Institute of Allergy and Infectious Diseases. Several drugmakers are now developing vaccines that could help us avoid many of the troubling symptoms of the tick-borne disease.