Lyme Vaccine Moves to Clinical Trials

The FDA recently approved an Investigational New Drug application submitted by Valneva SE, a biotechnology company based in France, allowing it to proceed with phase I clinical trials on a new vaccine for borrelioisis, more commonly known as Lyme disease.

According to the CDC, 30,000 cases of Lyme disease are reported each year by state health departments, though the agency notes that available surveillance data may under report the true incidence of the disease due to questionable reliability of currently available testing. Although the disease is considered by many researchers and clinicians to be readily treatable, the condition is shrouded in controversy as a significant number of those who are infected for extended periods of time prior to receiving treatment have symptoms that persist after completion of the antibiotic therapies indicated by broadly accepted guidelines.

Lyme disease presentation can be varied and complex. The disease, thought to be caused by the bacteria Borrelia burgdorferi, is transmitted to humans through the bite of ticks carrying the infection. The hallmark sign of the infection is a red “bull’s-eye” rash at the site of infection, though many of those infected do not notice the rash or the tick transmitting the infection, which leads to many cases being undiagnosed early in the course of illness.

Infection with the bacteria is detected through the enzyme-linked immunosorbent assay (ELISA), which looks for antibodies generated subsequent to the infection, and then confirmed using the Western-blot test. Whereas the diagnostic tests for the disease looks for an immune response to the bacteria, rather than the presence of the bacteria itself, false negatives early in the disease are common. ELISA sensitivity is reported to be only 64%, but is thought to approach 100% as the infection persists. This is problematic given that late-stage Lyme disease presentation is much more severe and includes symptoms such as fatigue, cardiac, and respiratory distress as well as neurologic symptoms, which may lead to misdiagnosis. Additionally, once an individual has tested positive, they will continue to show positive results in subsequent testing. This makes it impossible to test for persisting infections, or re-infections in patients who have been successfully treated for a previous case.

Valneva’s vaccine candidate, VLA15, would not be the first vaccine for Lyme disease to hit the market. In the 1990s, SmithKline Beecham released LYMErix, a product that was ultimately as controversial as the disease it sought to prevent. At the time of its release, the vaccine went for $50 per dose, and boasted over 75% efficacy. The vaccine was withdrawn in 2002 following a class-action lawsuit and claims that the vaccine caused autoimmune side effects, though these claims were never substantiated by the investigation conducted by the FDA and the CDC.

Although this is good news for groups that advocate to raise awareness about the disease and for those who advocate for stronger treatment and prevention measures, a release for the vaccine will still be a ways off. Additionally, this is only addresses part of the concerns associated with the disease. As cases of Lyme continue to increase in prevalence across the United States and Europe, additional research into testing and treatment options for persistent symptoms will be necessary to address this growing health crisis before it reaches critical mass.