Coronavirus Global situation

Fast-spreading Delta variant challenges China's virus defence

Residents in Nanjing, Jiangsu province, getting tested yesterday as China confronts its most widespread coronavirus outbreak in months. The country's vaccination rate is close to 60 per cent but it remains to be seen if its locally developed shots ca
Residents in Nanjing, Jiangsu province, getting tested yesterday as China confronts its most widespread coronavirus outbreak in months. The country's vaccination rate is close to 60 per cent but it remains to be seen if its locally developed shots can slow the Delta's spread. PHOTO: AGENCE FRANCE-PRESSE

BEIJING • China is confronting its broadest Covid-19 outbreak since the pathogen was first detected in the country in late 2019, with the Delta variant spreading to places that had been declared virus-free for months.

The Delta variant has broken through China's virus defences, among the world's strictest, and reached nearly half of China's 32 provinces and regions in just weeks. While the overall number of cases - more than 300 so far - is still lower than resurgences elsewhere, the wide spread indicates that the variant is moving quickly.

It is the biggest challenge to China's strategy since the coronavirus was first detected in Wuhan city in December 2019. The country's anti-virus measures, which include mass testing, aggressive contact tracing, widespread use of quarantines and targeted lockdowns, have crushed more than 30 flare-ups over the past year. But the more infectious Delta variant is testing that approach.

The new strain may be exploiting an easing off in masking and social distancing in some places, since much of the country has been virus-free for months. That, along with increased travel for summer vacation, created a viable environment for it to spread.

China yesterday reported 99 infections, including 44 who tested positive but have no symptoms. It is the biggest outbreak since a flare-up in Hebei province in January that had 2,000 infections.

The broad spread is more concerning, with infections having reached the highly protected capital Beijing, and Wuhan, the provincial capital of Hubei.

Wuhan yesterday said seven migrant workers tested positive, its first cases since its original wave.

The initial Delta infection arrived in the eastern city of Nanjing from Moscow in mid-July. Within weeks, cases have popped up as far away as Hainan island in the south.

China's vaccination rate is close to 60 per cent and among the world's highest, but it remains to be seen if its locally developed shots can slow the Delta's spread.

Most of those infected in Nanjing were immunised, and the vaccines - which have been found to be less effective than mRNA shots in clinical trials - do appear to be providing protection, with only 4 per cent of those infected battling severe disease. Many of them also have pre-existing conditions.

While all vaccines are proving less effective against the Delta variant, there are concerns that non-mRNA shots like the Chinese ones and AstraZeneca's shot will be less able to slow transmission.

State-owned Sinopharm has said its inactivated shot is 68 per cent effective against the variant, citing a study in Sri Lanka. Sinovac Biotech said the antibodies induced by its shot can still neutralise the Delta strain in laboratory studies.

Adding to the concern is a separate Delta cluster in Zhengzhou - provincial capital of Henan - where hospital and cleaning staff have been infected. Cases were also reported in the surrounding areas of the city, where the officials' ability to curb the spread of the virus may be weakened due to recent deadly floods.

Also affected are those living in Zhangjiajie, where a live outdoor performance a week ago with more than 3,000 spectators fuelled the virus' spread.

Officials in Beijing - which has detected five Delta cases so far - have vowed to cut off the virus' transmission with "the fastest pace, strictest measures and the most decisive actions". The capital will tighten entry rules for those entering from places with outbreaks, and government and state company staff have been barred from leaving the city.

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A version of this article appeared in the print edition of The Straits Times on August 03, 2021, with the headline Fast-spreading Delta variant challenges China's virus defence. Subscribe