World May 21, 2021 COPENHAGEN: Progress against the coronavirus pandemic remains "fragile" and international travel should be avoided, a World Health Organisation director warned on Thursday, while stressing that authorised vaccines work against variants of concern. "Right now, in the face of a continued threat and new uncertainty, we need to continue to exercise caution, and rethink or avoid international travel," WHO’s European director Hans Kluge said, before adding that "pockets of increasing transmission" on the continent could quickly spread. The so-called Indian variant, which might be more transmissible, has now been identified in at least 26 of the 53 countries in the WHO Europe region, Kluge said during his weekly press conference.