The Delta variant of the coronavirus is becoming the globally dominant strain due to its "significantly increased transmissibility", the World Health Organisation's (WHO) chief scientist has said.
Dr Soumya Swaminathan's comments came as officials in countries such as the United States, Britain, Germany and Russia urged more people to get vaccinated, warning that the more transmissible strain could cause more deaths.
Eighty countries have so far reported cases of the Delta variant, according to a WHO weekly epidemiological report.
Studies suggest that Delta, first identified in India, is around 60 per cent more transmissible than Alpha, the variant first identified in Britain that was more contagious than the strain that emerged from the Chinese city of Wuhan late in 2019.
"The Delta variant is well on its way to becoming the dominant variant globally because of its significantly increased transmissibility," said Dr Swaminathan on Friday (June 18). The situation globally is "so dynamic because of the variants that are circulating", she added.
WHO is particularly concerned about Africa. Although the continent accounts for only around 5 per cent of new infections and 2 per cent of deaths, new cases in Namibia, Sierra Leone, Liberia and Rwanda have doubled in the past week.
"It's a trajectory that is very, very concerning", while vaccine access remains minuscule, said WHO emergencies programme head Mike Ryan.
"The brutal reality is that in an era of multiple variants, with increased transmissibility, we have left vast swathes of the population, the vulnerable population of Africa, unprotected by vaccines."
In Singapore, experts say the Delta variant could have driven recent outbreaks at hawker centres and wet markets, including Redhill Market and Food Centre, and Telok Blangah Drive Food Centre and Market.
The authorities have dialled back some reopening plans for tomorrow. Dining in, for instance, will be allowed but limited to two diners per table instead of five as planned.
Indonesia expects a new wave of infections to peak early next month, as the Delta variant becomes more dominant in some areas and with the occupancy of hospitals in Jakarta hitting some 75 per cent.
In the US, President Joe Biden noted that areas where the vaccination rate is falling short are showing more infections, and warned that those who decline to get vaccinated risk becoming infected by the highly contagious variant.
The Delta variant accounts for 6 per cent of cases nationwide, but 18 per cent of cases in Colorado, Montana, North Dakota, South Dakota, Utah and Wyoming.
The variant could become the dominant strain in the US this summer, said Centres for Disease Control and Prevention director Rochelle Walensky.
As at Friday, just over 65 per cent of people in the US have received at least one dose of the vaccine, but the vaccination rate has slowed over the past two weeks.
Across Russia, only 9.9 per cent of the population is said to be fully vaccinated and new cases have spiked.
Moscow Mayor Sergei Sobyanin said 89.3 per cent of new cases in the city of over 12 million involved the Delta variant.
Britain has also reported a steep rise in infections with the Delta variant, which accounts for over 90 per cent of new cases particularly among young people - prompting the government to delay plans to lift social contact restrictions to July 19.
In Germany, the Delta variant accounted for a little over 6 per cent of new cases, but the figure has been rising in recent weeks.