Admin_Adham
Jump to Key Points Tick season is in full swing, and reported data from several German states point to a marked rise in Lyme disease cases. Yet prevention and diagnosis are failing to keep pace with the trend, which is also being seen in many other countries.
In a recent article in JAMA, Linden Hu, MD, co-director of the Lyme Disease Initiative at Tufts University School of Medicine in Boston, offers a sobering assessment: “Frankly, it’s depressing that we’ve been doing the same thing with Lyme disease for 25 years.”
Treatment isn’t the problem: when detected early, the disease caused by Borrelia burgdorferi can generally be treated effectively with antibiotics. “But when it comes to prevention, early detection, and chronic Lyme disease, we clearly haven’t done a good job,” says Hu.
Alternative to the Antibody Test
That doesn’t mean nothing is being done. In the field of diagnostics, efforts are underway to find an alternative to the established antibody tests. This is because the antibody response can take 2-6 weeks to develop. During this early phase, tests can come back negative despite an existing infection.
- Lyme incidence ↑ in several German states; underreporting likely due no nationwide mandate.
- Early Lyme dx still limited by 2-6 week antibody lag; direct detection remains difficult.
- LB6V phase III: 73% efficacy; 3 doses/9 months + booster may limit uptake.
- Preexposure mAb protection begins within 2 days; likely annual infusion, higher cost.
- Lotilaner aims to kill attached ticks before ≥36-hour transmission window; routine use years away.
Among other things, methods for the direct detection of antigens or bacterial DNA are currently under development. Other approaches focus on the host’s response and use AI to analyze gene expression patterns of the immune system. However, direct detection of the bacterium remains difficult: B burgdorferi is found primarily in the skin and tissues and only in very small numbers in the blood.
While new approaches are emerging, a true diagnostic breakthrough still does not appear to be imminent. That point is underscored in a JAMA article by Paul G. Auwaerter, MD, director of the Fisher Center for Environmental Infectious Diseases at the Johns Hopkins School of Medicine in Baltimore, who wrote that “enabling earlier diagnosis remains one of the major unresolved goals.”
A New Push in Vaccine Development
As long as an infection cannot be reliably detected early, prevention becomes all the more important. Yet even in the development of a vaccine against Lyme disease, things had been quiet for a long time.
In the late 1990s, LYMErix became the first vaccine against Lyme disease to be approved in the US. In studies, it reduced new infections in adults by nearly 80%. But just a few years later, following disappointing sales figures and amid concerns about potential side effects, the manufacturer voluntarily withdrew it from the market. A causal link between the vaccine and the suspected side effects was not confirmed later on.
“The experience with LYMErix may have deterred pharmaceutical companies from getting involved in this field for years,” reported Auwaerter. “It is only in the past 3-4 years that interest in this aspect of prevention has risen significantly again.”
The leading vaccine candidate at present is LB6V, a multivalent recombinant protein vaccine developed by Pfizer and Valneva, as Medscape’s German edition reported. In March 2026, the companies announced phase III data showing that the vaccine was 73% effective against Lyme disease.
Prevalence of Lyme disease in Germany
Under the Infection Protection Act, there is no nationwide reporting requirement for Lyme disease. The Robert Koch Institute, Berlin, Germany, therefore, explicitly points out that the exact prevalence in Germany is unknown. However, reporting requirements under state law exist in the following states:
- Bavaria
- Berlin
- Brandenburg
- Mecklenburg-Western Pomerania
- Rhineland-Palatinate
- Saarland
- Saxony
- Saxony-Anhalt
- Thuringia
The available data show a significant increase in several of these federal states for 2025. In Berlin, 1406 cases had been recorded by mid-December — more than ever before since mandatory reporting was introduced in 2013. In Brandenburg, the number of reported cases reached 2612 — or 102 cases per 100,000 residents — marking the highest incidence since the reporting regulation was introduced in 2001. And in Bavaria, 4156 cases had already been reported by early September, about one third more than during the same period the previous year.
New Vaccine Candidate Meets with Skepticism
However, some of the experts interviewed by JAMA view the candidate with skepticism. Among them is Nicole Baumgarth, PhD, director of the Lyme and Tickborne Diseases Research and Education Institute at the Johns Hopkins Bloomberg School of Public Health in Baltimore. Among other concerns, she pointed out that despite a revised formulation, LB6V targets the same antigen as LYMErix — outer surface protein A (OspA) from B burgdorferi. “We took it off the market, and 20 years later, we’re basically just replacing it with the same antigen,” she said.
The vaccination schedule could also prove challenging, requiring three doses over 9 months followed by a booster. Hu therefore worries the vaccine may face limited acceptance: The more prevention options available, the better, but it’s likely to be difficult to convince people to get four doses.
Also unresolved is how long protection from the vaccine will last. Baumgarth suspects that its effect could fade within a year, just enough to get through tick season, and with climate change, tick season is getting longer and longer, she said.
Antibodies Are Expected to Provide Faster Protection
In parallel with vaccine development, other prevention strategies are therefore being investigated — especially for people who need protection in the short term. One approach is preexposure prophylaxis using a monoclonal antibody that also targets OspA. Unlike with a vaccine, protection begins almost immediately.
“Protection is established within 2 days of the infusion,” said Auwaerter. However, an annual infusion at a medical facility would likely be required. And production and administration are likely to be costly.
According to Baumgarth, such preexposure prophylaxis could be particularly beneficial for people who are only temporarily at increased risk for exposure — such as during an extended vacation spent largely in nature.
From Dog Chews to Human Tick Protection
Tarsus Pharmaceuticals is pursuing a completely different approach with the orally administered active ingredient lotilaner. It is already approved for human use as eye drops to treat Demodex blepharitis and is used in pets as a chewable tablet against fleas and ticks.
The idea behind it: Instead of fighting the bacterium, lotilaner is designed to kill the tick shortly after it attaches, thereby preventing the transmission of B burgdorferi and other pathogens. Ticks must remain attached for about 36 hours or longer for transmission to occur. If ticks attach but fall off again within a few hours, you are essentially protected from contracting Lyme disease.
Experts see definite potential in such new prevention strategies. However, it will likely be years before they become part of routine clinical practice.
For Now, Only Traditional Tick Prevention Measures Remain
For the time being, the familiar measures for preventing Lyme disease remain: using tick repellent, wearing protective clothing, checking the body for ticks after spending time outdoors, and removing attached ticks as quickly as possible.
“This works,” said Baumgarth. “It simply requires that doctors be made aware of it and that the public be educated — especially in regions that are not traditionally considered endemic areas.”
This story was translated from Medscape's German edition.
