Summer in the U.S. is now in full swing. That means plenty of outdoor fun, Sun, and, unfortunately, for many of us, tiny eight-legged ticks to avoid.
Ticks and the many illnesses they carry, like Lyme disease, are a growing public health threat. Just this week, for instance, the latest data from the Centers for Disease Control and Prevention showed that 2025 so far has seen the highest number of tick-related emergency room visits recorded since 2019. And though the worst tick species are especially common in the Northeast, disease-carrying populations are steadily spreading further across the U.S. What’s more, scientists are still continuing to discover new viruses and bacteria spread by ticks that can potentially sicken people.
With Americans firmly in the middle of hot tick summer, Gizmodo reached out to Dennis Bente, a professor of microbiology and immunology at the University of Texas Medical Branch. We spoke to Bente about why ticks are becoming a bigger problem, the best ways right now to protect ourselves against them, and the potential innovations that could eventually help us beat back the tick menace. The following conversation has been lightly edited for grammar and clarity.
Ed Cara, Gizmodo: I live in the northeastern U.S., and my friends and family, especially dog owners, often complain about needing to look out for ticks sooner than they used to. Is the tick season really getting longer and larger? And what seem to be the major reasons why?
Bente: Yes, your friends and family are absolutely correct in their observations. The tick season in the Northeastern United States has indeed become longer and more intense, with multiple scientific studies confirming both the expansion of tick activity periods and the growth of tick populations.
What was once a relatively predictable seasonal threat has evolved into a year-round concern in many areas. The evidence shows that ticks are now active in winter due to climate change, with adult deer ticks active at temperatures as low as 14 degrees Fahrenheit [-10 degrees Celsius]. This has led to a year-round need for vigilance, as ticks now emerge whenever the ground is unfrozen and temperatures exceed freezing, extending their season beyond traditional months. Climate warming accelerates tick development, increases survival, and enables northward expansion at about 28 miles [45 kilometers] per year, especially in the Northeast. Factors like recovering deer populations, reforestation, landscape fragmentation, and fire suppression have also promoted tick populations by providing ideal habitats and microclimate regimes that favor tick survival.
Gizmodo: When it comes to tick germs, people are probably most familiar with Lyme disease. But there are plenty more out there. What are some of the lesser-known tickborne diseases that keep you up at night? And are these diseases, like Lyme, becoming more common?
Bente: While Lyme disease dominates public awareness of tickborne illnesses, it represents just the tip of a much larger iceberg.
Powassan virus (POWV) stands out as perhaps the most frightening tickborne pathogen in North America. This flavivirus can cause severe encephalitis with mortality rates approaching 18.8% and devastating neurological consequences in 72.7% of survivors. Unlike other tickborne diseases, POWV can be transmitted within just 15 minutes of tick attachment, giving victims almost no opportunity for preventive tick removal.
There are also other less-known viruses. The Heartland virus emerged in 2009 and has since been documented in over 60 cases across 14 states, with an estimated mortality rate of 5-10%. Bourbon virus (BRBV) was first identified in 2014 and remains poorly understood. Only 5 human cases have been reported in Kansas, Oklahoma, and Missouri, but blood tests suggest that it is much more widespread.
Borrelia miyamotoi causes hard tick relapsing fever, a disease that often goes undetected despite being transmitted by the same ticks that carry Lyme disease. Between 2013 and 2019, 300 cases were identified through surveillance in just nine states that conduct active monitoring. This likely represents massive underreporting, as the disease is often misdiagnosed.
There is also Ehrlichia and the spotted fever group rickettsiae, which represent a growing and increasingly complex threat. While Rocky Mountain spotted fever (Rickettsia rickettsii) remains the most severe, newly recognized rickettsial pathogens are emerging that can cause similar severe illness.
Overall, tickborne diseases are absolutely becoming more common. The evidence is overwhelming: Total tickborne disease cases in the US increased 25% from 40,795 (2011) to 50,856 (2019).
Gizmodo: Are there any treatments, vaccines, or other innovations in development that could possibly help us beat these germs?
Bente: Yes, there are indeed promising treatments, vaccines, and innovative technologies in development that could help us finally gain the upper hand against tickborne diseases.
Here’s what’s on the horizon: The most significant immediate breakthrough is VLA15, the first Lyme disease vaccine to reach advanced clinical trials in over two decades. Developed jointly by Pfizer and Valneva, this represents a major advancement over previous failed attempts. The vaccine has completed recruitment for its Phase 3 VALOR trial with 9,437 participants enrolled across the United States, Europe, and Canada. Results are expected by the end of 2025, with potential regulatory approval in 2026.
Perhaps even more exciting than pathogen-specific vaccines are anti-tick vaccines that could prevent multiple tickborne diseases simultaneously by targeting the tick itself. Researchers have developed mRNA-lipid nanoparticle vaccines containing cocktails of tick salivary proteins. The most advanced formulation is the 19ISP vaccine. This vaccine causes rapid erythema development in the skin, early tick detachment, and decreased tick feeding by creating an immune response that alerts hosts to tick presence and prevents pathogen transmission when ticks are removed promptly.
TP-05 is an investigational oral, systemic formulation of lotilaner developed by Tarsus Pharmaceuticals; it represents a revolutionary approach to tickborne disease prevention. This isoxazoline compound has successfully completed Phase 2a human trials, demonstrating 97% tick mortality within 24 hours of attachment, with a single dose providing protection for at least 30 days. Since ticks typically require 36 to 48 hours of attachment to transmit Lyme disease, killing them within 24 hours provides highly effective prophylaxis with an excellent safety profile in healthy volunteers.
Gizmodo: In the meantime, how do we best keep these tiny pests from ruining our time outdoors?
Bente: For reliable tick protection, the Centers for Disease Control and Prevention recommends EPA-registered repellents containing DEET, picaridin, IR3535, or Oil of Lemon Eucalyptus (OLE). Research consistently shows that DEET concentrations of 20 to 30% provide the most effective protection, with efficacy rates of 85 to 89% against ticks.
Permethrin, readily available in stores, stands out as perhaps the most powerful weapon in your anti-tick arsenal. Unlike repellents that simply deter ticks, permethrin actually kills ticks on contact. When applied to clothing, it can provide protection for up to six weeks or six washes. The effectiveness is remarkable: permethrin-treated clothing has shown nearly 100% protection against tick attachment.
Your clothing choices can serve as your first line of defense. Wear light-colored clothing to make ticks easier to spot. Long-sleeved shirts, long pants, and closed-toe shoes provide physical barriers, and tucking your shirt into pants and pants into socks creates additional protection by eliminating entry points.
Stay on trail centers and avoid wooded, brushy areas during peak tick season (April to September). Daily tick checks are the most critical prevention measure. Most tickborne diseases require 24 to 48 hours of attachment for transmission, so quick removal dramatically reduces infection risk. Check your entire body using mirrors, focusing on warm areas: groin, armpits, scalp, behind ears and knees, and waistbands. Check children and pets daily, even after yard time, and shower within 2 hours to wash off crawling ticks.
For proper removal, use fine-tipped tweezers to grasp the tick close to the skin. Pull upward with steady pressure—don’t twist or jerk. Don’t squeeze, crush, or burn the tick. Clean the bite area and hands with alcohol or soap. Be sure to photograph the tick for identification if symptoms develop and avoid folk remedies like matches or nail polish—these increase disease transmission risk.
