In April 2023 the UKHSA issued a press release explaining the risk assessment produced by HAIRS on the risk presented to the UK population by tick-borne encephalitis virus (TBEV). HAIRS is the Human Animal Infections Risk Surveillance group, a multi-agency cross-government organisation that “acts as a forum to identify and discuss infections with potential for interspecies transfer”. The conclusion of the assessment is that the risk to the “general public in the UK” remains “very low”.  

TBEV in the UK 

The statement from UKHSA describes the virus as “carried by ticks” and “common in many parts of the world”. It can cause a range of disease, from “asymptomatic infection” to flu-like illness, to “severe infection in the central nervous system”.  

The report details 3 cases of probable or confirmed TBEV in England since 2019. One was linked to the Yorkshire area in 2022, and previous detection has covered Hampshire and Dorset, and Norfolk and Suffolk border areas. However, the tick species that carries the virus is “widespread in the UK”, meaning that it may be present elsewhere.  

Dr Meera Chand, Deputy Director at UKHSA indicated that the virus is “very uncommon in the UK”. Therefore, the risk to the population is “very low”. 

“Ticks also carry various other infections, including Lyme disease, so take steps to reduce your chances of being bitten when outdoors in areas where ticks thrive.”  

Risk assessment 

The risk assessment is based on the human cases that have been identified and the detection of the virus in ticks across the country.  

  • Probability – very low for the general population and low for high-risk groups (this includes those living and working in affected areas) 
  • Impact – low 
  • Level of confidence in assessment of risk – high  

The actions and recommendations set out by HAIRS include raising local awareness on tick avoidance measures and updating the national guidance to raise awareness among NHS staff. 

“Apply serology to understand the extent of unascertained disease in humans.” 

Increased testing in “clinically compatible UK-acquired encephalitis or neurological symptoms following a febrile illness” is recommended. In the first instance, testing is carried out with a serological assay at the Rare and Imported Pathogens Laboratory (RIPL). 

“Consideration of whether vaccination of high-risk groups such as forestry workers is warranted at this stage, while further studies looking for evidence of human exposure or infection are undertaken.”  


Professor Ian Jones of Reading University told The Mirror that “the vaccine already exists” and that other European countries already use it. 

“It’s there, it’s used, it’s safe, we don’t need to invent a new one.”  

Although it “could be used”, Professor Jones believes that “at the moment the cases wouldn’t support it”. He echoed the UKHSA message that it doesn’t represent a “particular threat to people”. 

“The main thing is people just need to be aware of it but it’s not a human threat in that sense in any large scale.” 

To participate in discussions about vaccinating against veterinary and human infections, join us at the World Vaccine Congress in Europe later this year.