The highly-contagious Delta variant of Covid-19 is a warning to the world to defeat the virus quickly before it mutates again into something even more dangerous, the WHO warned on Friday.
The most virulent variant of coronavirus, first detected in India, has now been found in 132 countries, the World Health Organisation said.
"Delta is 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," AFP news agency cited WHO's emergencies director Michael Ryan as saying at a press conference in Geneva.
However, Ryan also said that proven measures to bring transmission under control still worked. These include physical distancing, wearing masks, hand hygiene and avoiding long periods indoors in poorly ventilated, crowded places.
Also read: US sees big role for India as vaccine supplier in Covid war as China-made shots flop
"The virus has got fitter, the virus has got faster. The game plan still works, but we need to implement and execute our game plan much more efficiently and much more effectively than we've ever done before" he added.
WHO chief Tedros Adhanom Ghebreyesus said COVID-19 infections have increased by 80% over the past four weeks in most regions of the world. Deaths in Africa, where only 1.5% of the population is vaccinated, also rose by 80% over the same period.
The statement assumes significance as the WHO is a strong proponent for a more equitable distribution of vaccines to fight the pandemic.
"Hard-won gains are in jeopardy or being lost, and health systems in many countries are being overwhelmed," Tedros said at the news conference.
"So far, four variants of concern have emerged, and there will be more as long as the virus continues to spread," he explained.
Maria van Kerkhove, WHO technical lead on COVID-19, said the Delta variant was the most easily spread so far, about 50% more transmissible than ancestral strains of SARS-CoV-2 that first emerged in China in late 2019.
A few countries had reported increased hospitalisation rates, but higher rates of mortality had not been recorded from the Delta variant, she said.
