The Delta variant of COVID-19, first identified in India, is becoming the globally dominant variant of the disease, the World Health Organization's chief scientist said on Friday.
Soumya Swaminathan also voiced disappointment in the failure of CureVac's vaccine candidate in a trial to meet the WHO's efficacy standard, in particular as highly transmissible variants boost the need for new, effective shots.
Britain has reported a steep rise in infections with the Delta variant, while Germany's top public health official predicted it would rapidly become the dominant variant there despite rising vaccination rates.
CureVac's vaccine has proved only 47% effective.