SHANGHAI: The city of Shanghai hasdiscovered a COVID-19 case involving a new subvariant Omicron BA.5.2.1, an official told a briefing on Sunday, signalling thecomplications China faces to keep up with new mutations as itpursues its “zero-COVID” policy.

The case, found in the financial district of Pudong on July8, was linked with a case from overseas, said Zhao Dandan,vice-director of the city’s health commission.

Shanghai, in eastern China, emerged from a lockdown lastingaround two months at the start of June, but it has continued toimpose tough restrictions, locking down buildings and compoundsas soon as new potential transmission chains emerge.

“Our city has recently continued to report more locallytransmitted positive cases (of COVID-19) and the risk of theepidemic spreading through society remains very high,” Zhao ofthe Shanghai health commission warned.

He said residents in several major Shanghai districts wouldundergo two rounds of COVID tests, from July 12-14, in a bid tobring potential new outbreaks under control.

The Omicron BA.5 variant, which is driving a new wave ofCOVID-19 infections overseas, was first discovered in China onMay 13 in a 37-year old male patient who had flown to Shanghaifrom Uganda, according to the China Center for DiseasePrevention and Control.

Variant BA.5 has been shown to have an accelerated rate oftransmission and an improved immune escape capability, said YuanZhengan, a member of the city’s expert advisory group on COVIDprevention, speaking at the Sunday briefing.

But vaccination is still effective at preventing BA.5 fromcausing serious illness or death, he added.