VCU news

By Dedrain Davis

Researchers at the Virginia Commonwealth University School of Medicine have received a $2.54 million grant from the National Institutes of Health for the development of vaccines to prevent Lyme disease and human granulocytic anaplasmosis, the two most common tick-borne infections in the United States.

The four-year award was granted to a research team co-led by Richard T. Marconi, Ph.D., and Jason Carlyon, Ph.D., professors in the Department of Microbiology and Immunology.

The Marconi lab previously developed a canine Lyme disease vaccine that entered the U.S. veterinary market in 2016. More recently, the researchers developed a prototype vaccine antigen for anaplasmosis in canines. The vaccine is currently undergoing testing.

“The goal of the NIH funding is to redesign the canine Lyme disease and Anaplasma vaccines for use in humans,” Marconi said.

Lyme disease and anaplasmosis are caused by the bacteria Borrelia burgdorferi and Anaplasma phagocytophilum, respectively. Both diseases are transmitted to humans and animals through the bite of an infected Ixodes tick (commonly referred to as the blacklegged tick or deer tick). The Centers for Disease Control and Prevention estimates over 300,000 new cases of Lyme disease each year in the U.S. and approximately 100,000 cases in Europe. While approximately 5,700 cases of anaplasmosis are reported each year in the U.S., due to misdiagnosis and underreporting its true incidence is thought to be much higher.

Because of the expanding geographic range of the blacklegged tick, the incidence of Lyme disease and anaplasmosis is increasing. Tick-borne diseases are a growing public health threat through much of North America and Europe.

The new grant, along with funding from the Stephen & Alexandra Cohen Foundation, The National Christian Foundation and existing NIH awards, will support the team’s work to develop a combination Lyme disease/anaplasmosis vaccine.

“The advantage of this approach,” Carlyon said, “is that a single vaccine formulation, as opposed to two separate vaccines, can be used to protect against these potentially debilitating diseases.”

Lyme disease and Anaplasma vaccines for use in humans are not currently available. A vaccine for human Lyme disease called LYMErix, available from 1998 to 2002, was discontinued because of declining sales due to perceived concerns about possible adverse effects. 

The generally nondescript clinical manifestations of early-stage Lyme disease and anaplasmosis (rash, fever, headache, chills and muscle aches) means cases often go undiagnosed. In the absence of early intervention, Lyme disease can become a chronic infection with symptoms that persist indefinitely.

“There is an urgent need to develop new preventative strategies, as well as therapeutics and diagnostics, for these important diseases,” said Marconi, who developed a screening tool in 2017 to detect Lyme disease in humans. “The research being conducted by our laboratories occupies an important niche. The development of effective vaccines for tick-borne diseases is considered a high priority by the NIH and the CDC.”