China, the ground zero of COVID-19,  is now grappling with the spread of the highly-contagious Delta variant. The outbreak that started at an airport in the eastern Chinese city of Nanjing is spreading fast and seeding infections in other regions. The outbreak in one of the world’s largest economies is a serious setback to revival attempts.

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Despite a well-oiled machinery of testing, contact tracing and containment, Chinese authorities are struggling to contain the strain that was first reported in India. China’s Wuhan reported the first known case of COVID-19 in December 2019 triggering speculation that the virus was made in a lab.

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The current Delta variant outbreak began after nine workers at the Nanjing airport tested positive on July 20. The infection has since spread to at least four other provinces. “It is geographically the largest spread for several months, challenging China’s aggressive containment efforts which have relied on mass testing, lockdowns and swift contact tracing,” reports cna.com.

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Hundreds of thousands of residents have been locked down and Internet cafes, gyms, cinemas and libraries in Nanjing have been shut down. The city has tested all 9.2 million residents twice and in  a worrying trend most of the patients testing positive have already been vaccinated. China has vaccinated at least 65 % of its 1.5 billion population.

The Delta variant is spreading fast in many countries, including the US, UK, southeast Asian countries, Australia and Europe. Among the hardest hit is Australia, where Sydney has been pushed into weeks of lockdown, with cases climbing to nearly 3,000 since mid-June.

The US, which had discontinued the mask rule for fully-vaccinated people, has brought back the stipulation after Delta variant infectio  was reported among the fully-vaccinated too.

With more than 1,300 deaths in a day, Indonesia has become Asia’s new COVID hotspot, fuelled by the Delta variant.