Authorized COVID-19 vaccines are effective against all known variants, including the new strain causing the current wave in India, Europe Director of the World Health Organization Hans Kluge said on Thursday. 

Kluge also warned that progress against the pandemic remains "fragile" and said international travel is not yet safe. "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," he added.