Tick-borne illnesses continue to rise across the U.S. and Europe, and clinicians are feeling the impact. More patients are showing up with early Lyme disease, more are asking about prophylaxis, and more travelers want advice about tick-borne encephalitis (TBE). At the same time, vaccine development is finally accelerating after years of stagnation. For busy clinicians, here is a concise update on what’s new and what to tell patients in 2025.

Lyme disease remains the most reported vector-borne illness in the U.S. In 2023, national case counts surpassed 89,000, with estimates suggesting nearly half a million people are diagnosed and treated each year. Beyond raw numbers, clinicians are seeing a broader geographic spread: cases in counties that rarely reported Lyme before, longer tick seasons, and more bite exposures in previously “low-risk” areas. Climate shifts, warmer winters, and expanding deer and rodent populations have all contributed. For clinicians, this means maintaining a higher index of suspicion, especially when patients present with summer flu-like illness, new rashes, or unexplained neurologic symptoms.

The Lyme vaccine landscape in 2025

The withdrawal of LYMErix in 2002 left a long shadow, but the science has moved on. Importantly, extensive reviews have found no evidence that LYMErix caused autoimmune arthritis, the concern that dominated public discussion at the time. Today’s leading candidate is VLA15, a multivalent OspA-based vaccine developed by Pfizer and Valneva. It targets the most common Borrelia serotypes in North America and Europe. The vaccine is now in Phase 3, with more than 9,000 participants having completed the primary series. Booster doses continue in 2025, and efficacy data are expected in 2026.

Early-phase studies show:

• Strong immunogenicity
• Broad coverage
• Good tolerability
• Promise for seasonal or semi-seasonal dosing

Clinicians should monitor for guidance on booster intervals, use in children, co-administration with influenza/COVID-19 vaccines, and safety in people with prior Lyme infection or autoimmune conditions.

Monoclonal antibody “Lyme PrEP”

Another strategy gaining traction is seasonal anti-OspA monoclonal antibodies, which neutralize Borrelia inside the tick before transmission. A long-acting antibody (TNX-4800) was licensed for development in 2025, underscoring industry interest. If successful, this could offer once-per-season protection, especially useful for travelers, outdoor workers, or individuals who prefer a passive immunization approach.

Clinical reminders: Lyme treatment and prophylaxis

The core management of Lyme disease remains consistent:

• Early localized disease: Is effectively treated with doxycycline, amoxicillin, or cefuroxime.
• Post-exposure prophylaxis: A single 200-mg dose of doxycycline (or weight-based dosing in children ≥8 years) within 72 hours of removing a high-risk Ixodes tick is recommended.
• Erythema migrans: Treat immediately; no labs needed.

Clinicians should reassure patients: Early Lyme disease is highly treatable, and early intervention prevents complications.

Tick-borne encephalitis

TBE is not endemic in the U.S., but American and European travelers are increasingly heading to countries where the virus is established, Central and Eastern Europe, Scandinavia, the Baltics, and alpine regions. The FDA-approved vaccine TICOVAC (2021) has made prevention straightforward in the U.S.:

• Approved for ages 1 and older
• 3-dose primary series with boosters
• Strong real-world effectiveness

ACIP’s 2023 recommendations support vaccination for travelers with substantial tick exposure and laboratory workers handling the virus.

Outside the U.S., both TICOVAC (FSME-IMMUN) and Encepur are widely used. Encepur offers two schedules:

• A conventional schedule spread over several months
• An “Express” schedule that completes the three priming doses in as little as 21 days

For last-minute travelers, Encepur Express can be critical. In practical terms, when you see a patient with imminent travel to a TBE-endemic area and access to Encepur, you can explain that the rapid schedule still generates protective antibody levels before departure, with boosters needed to maintain long-term immunity.

Whether using TICOVAC or Encepur, clinicians should help patients understand that:

• Protection improves with each dose
• Completing at least two doses before travel is far better than none
• Boosters are essential for ongoing coverage in those with repeated exposure

Travel medicine practices should proactively ask about outdoor activities, rural exposure, planned hikes, and camping, details that strongly influence TBE risk.

Babesiosis: increasing, serious, and vaccine-free

Babesiosis has expanded significantly in the Northeast and upper Midwest. Cases are increasingly severe among older adults and immunocompromised individuals. Key management points:

• Preferred therapy: Atovaquone + azithromycin
• Alternative: Clindamycin + quinine
• Severe disease: Consider exchange transfusion
• Immunocompromised patients: May require longer courses and repeat PCR testing

There is currently no vaccine, and although research continues, clinical options remain limited to early detection and appropriate treatment.

Powassan virus: rare but clinically important

Powassan virus (POWV) remains uncommon but poses a high risk of neuroinvasive disease. There are no vaccines or antivirals, and management is supportive. Several preclinical vaccine platforms show promise, but none are close to human trials. Clinicians should consider Powassan in patients with compatible symptoms and a history of tick exposure in endemic regions. Prevention counseling, repellents, treated clothing, and daily tick checks, is essential.

Kyasanur Forest disease: a travel medicine consideration

Kyasanur Forest disease (KFD), found in parts of India, is a severe tick-borne viral infection that clinicians may encounter in travel clinics. A formalin-inactivated vaccine is used regionally in India, with multiple priming doses and boosters. Next-generation KFD vaccines are in development. While rare for U.S. clinicians to diagnose, KFD should be part of risk discussions for travelers heading to rural forested regions of Karnataka or nearby states.

What patients need to hear in 2025

Clinicians can offer a few clear, practical messages:

• “Tick seasons are longer and expanding geographically.” Protective clothing, repellents, and daily tick checks matter.
• “Early Lyme disease is highly treatable.” Prompt recognition reduces complications.
• “A Lyme vaccine is coming.” A Lyme vaccine may return within a few years, and new passive immunization tools are in development.
• “TBE vaccination is recommended for travelers to TBE endemic countries.” Two doses before travel is much better than none.
• “Not all tick-borne diseases have vaccines.” Babesiosis and Powassan rely on avoidance, early detection, and appropriate treatment.

Melvin Sanicas is an infectious disease physician.