Global warming is increasing the spread of tick-borne encephalitis and chikungunya viruses, the chief executive of vaccine maker Bavarian Nordic (BAVA.CO) said on Friday.
Bavarian Nordic's travel-health business benefits from strong vaccine demand. Sales of its chikungunya vaccine Vimkunya, which was approved in the U.S. and the European Union in February 2025, soared 415% in the second quarter, while revenue from its TBE shot Encepur rose 58%.
"The number of regions in Germany that are now considered to be at risk of TBE increases year after year," CEO Paul Chaplin told Reuters as an example of the company's major market being affected.
The disease is moving north each year from its traditional stronghold in southern Germany, Chaplin said, adding that TBE was also increasing in Scandinavia as warming climate and milder winters cause tick populations to grow and spread.
Last year, 693 TBE cases were reported in Germany, the third-highest number since the beginning of data collection in 2001, the Robert Koch Institute said in an epidemiological bulletin published in February. The institute also added two new risk areas.
Chaplin said chikungunya, a mosquito-borne disease typically found in Asia and South America, was also moving into Europe and the United States.
Mosquitoes capable of transmitting the disease are present in Europe, and imported cases of the virus can lead to local outbreaks, he said.
He noted previous local outbreaks in Italy and France, with France having reported locally acquired cases this year, according to the European Centre for Disease Prevention and Control.
Ambient temperature is among the most important environmental factors influencing mosquito-borne chikungunya transmission, ECDC said on its website.
"It's probably only a matter of time until chikungunya, unfortunately, is prevalent in southern Europe, but also in the States," Chaplin said.
