Cases of Lyme disease have increased by more than 20% in England over the past year, according to data from the UK Health Security Agency (UKHSA). There were 1,168 laboratory-confirmed cases in 2025, up from 959 in 2024, although the figure is similar to the 1,151 cases recorded in 2023.
The UKHSA also reported two probable cases of tick-borne encephalitis complex in 2025, bringing the total number of locally acquired cases to six since the virus was first identified in the UK in 2019. Dr Claire Gordon, head of the rare and imported pathogens laboratory at UKHSA, noted that case rates vary year to year depending on awareness, testing rates, and factors affecting outdoor activities such as weather.
Lyme disease is caused by the bacterium Borrelia burgdorferi, which lives in the gut of ticks found in grassy and wooded areas. Symptoms include a bullseye-like rash, fever, muscle and joint pain, and lethargy. If left untreated, the condition can become chronic. While not all ticks carry the bacteria, rapid removal reduces infection risk.
Currently, prevention advice for humans focuses on using repellents, covering exposed skin, and wearing light-coloured clothing. However, pharmaceutical companies are developing new vaccines and treatments. Moderna's mRNA vaccine is in phase 2 trials, while a vaccine from Pfizer and Valneva has shown over 70% efficacy in phase 3 trials and is to be submitted to regulators. Other approaches include monoclonal antibodies from Tonix Pharmaceuticals.
