Worldwide COVID-19 cases surpass 500 million as Omicron subvariant BA.2 surges

Global COVID-19 cases surpassed 500 million on Thursday, according to a Reuters tally, as the highly contagious BA.2 sub-variant of Omicron surges in many countries in Europe and Asia.

The rise of BA.2 has been blamed for recent surges in China as well as record infections in Europe, while South Korea leads the world in the daily average number of new cases, reporting more than 182,000 new infections a day and accounting for one in every four infections globally, according to a Reuters analysis.

New cases are rising in 20 out of more than 240 countries and territories tracked, including Taiwan, Thailand and Bhutan.

Shanghai is fighting China's worst COVID-19 outbreak since the novel coronavirus first emerged in Wuhan in late 2019, with almost 25,000 new local cases reported, although the city's quarantine policy is criticized for separating children from parents and putting asymptomatic cases among those with symptoms.

"Shanghai's epidemic prevention and control is at the most difficult and most critical stage," Wu Qianyu, an official with the municipal health commission, told a briefing.

In Canada, federal officials said the recent surge across Canada has been driven by the Omicron variant and its BA.2 subvariant.

Some European countries are now seeing a slower uptick in new cases, or even a decline, but the region is still reporting over one million cases about every two days, according to the Reuters tally.

In Germany, the seven-day average of new infections has fallen and is now at nearly 60 per cent of its previous peak in late March. New cases are also falling in the United Kingdom and Italy, while they are holding steady in France.

Overall, COVID-19 cases in the United States have dropped sharply after hitting record levels in January, but the resurgence of cases in parts of Asia and Europe has raised concerns that another wave could follow in the United States.

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The U.S. national public health agency said on Monday the BA.2 sub-variant of Omicron was estimated to account for nearly three of every four coronavirus variants in the country.

The BA.2 variant now makes up about 86 per cent of all sequenced cases globally, according to the World Health Organization. It is known to be more transmissible than the BA.1 and BA.1.1 Omicron sub-variants. Evidence so far, though, suggests BA.2 is no more likely to cause severe disease.

Scientists continue to emphasize vaccines are critical for avoiding the devastation the virus can cause.

Roughly 65 per cent of the world population has received at least one dose of a COVID vaccine, although only around 15 per cent of people in low-income countries have received at least one dose, according to figures from Our World in Data.