Delta is a warning: it's a warning that the virus is evolving but it is also a call to action that we need to move now before more dangerous variants emerge," the WHO's emergencies director Michael Ryan told a press conference.
WHO chief Tedros Adhanom Ghebreyesus added: "So far, four variants of concern have emerged -- and there will be more as long as the virus continues to spread." Tedros said that on average, infections increased by 80 percent over the past four weeks in five of the six WHO regions.
Though Delta has shaken many countries, Ryan said proven measures to bring transmission under control still worked -- notably physical distancing, wearing masks, hand hygiene and avoiding long periods indoors in poorly ventilated, busy