(210125) -- PARIS, Jan. 25, 2021 (Xinhua) -- File photo taken on April 21, 2020 shows a view of the Institut Pasteur in Paris, France. Institut Pasteur, one of France's main scientific research centers, announced on Jan. 25, 2021 that it has called off a development project of a COVID-19 vaccine candidate, which used the measles vector after a clinical trial showed that it was not good enough for immune responses. (Photo by Jack Chan/Xinhua) Xinhua News Agency / eyevine