A fast-spreading outbreak of the Delta coronavirus variant in China has caused rare infections among the country's vaccinated individuals, spurring authorities in Beijing to impose sudden travel restrictions.
China's National Health Commission on Tuesday reported 83 locally transmitted cases, with the majority detected in eastern Jiangsu province. The total number of infections from the outbreak stands at about 400.
Officials believe the main chain of transmission originated from a contaminated aircraft that arrived from Russia at Nanjing's main airport on July 10th.
Zhang Wenhong, an infectious diseases expert at the Huashan Hospital of Fudan University in Shanghai, confirmed at a press conference that some of those infected were airport staff who had already received vaccines, a phenomenon known as "breakthrough infection".
“There is no way that there could be no breakthrough cases among all the people who have been vaccinated,” he said. But he added that the efficacy of the Chinese-made jabs had been demonstrated by the fact that close contacts of the infected had tested negative for the disease.
Propelled by events at popular tourist destinations, the latest outbreak has spread rapidly to big cities. Although fewer than 10 cases were confirmed in Beijing, the local government cancelled trains, planes and buses to and from locations deemed risky.
Residents who had left the city on day trips were blocked from returning until they tested negative, according to videos circulated on Chinese social media.
The re-emergence of the virus in Wuhan, where the first cases of the virus were detected, also trended on Chinese social media on Tuesday after local health authorities reported 10 symptomatic cases in recent days. Authorities planned to test all of the city's residents for the virus, the second time it has done so, according to news agencies.
Wuhan’s hard-won and traumatic defeat of the virus remains politically sensitive for the ruling Chinese Communist party, which has trumpeted the victory as evidence of good governance.
Another cause of concern was the discovery of more than 60 infections in Zhengzhou, the capital of central Henan province. Last month, flooding engulfed huge portions of the city, trapping people in submerged subway cars and traffic tunnels.
On Monday, the official death toll from the disaster was raised from 99 to 302 with 50 people still missing.
Zhengzhou's Covid cluster was linked to an outbreak at a local hospital. Wang Songqiang, head of the Zhengzhou Centre for Disease Control, said the outbreak was in part due to "detrimental impacts on the hospital's coronavirus control efforts caused by the rainstorm". – Copyright The Financial Times Limited 2021