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Global warming widens spread of TBE, chikungunya, Bavarian Nordic boss says

By Thomson Reuters Aug 21, 2026 | 4:33 AM

By Vera Dvorakova

Aug 21 (Reuters) – Global warming is increasing the spread of tick-borne encephalitis and chikungunya viruses, the chief executive of vaccine maker Bavarian Nordic 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.

(Reporting by Vera Dvorakova in Gdansk; editing ​by Milla Nissi-Prussak)