While the number of cases are still relatively low compared to the United States and elsewhere, these new outbreaks — happening in cities such as Nanjing, Wuhan, Yangzhou and Zhangjiajie — are showcasing the limitations of China’s zero-tolerance approach to Covid. They may also undermine the ruling Communist Party’s argument that its authoritarian style has been an unquestionable success in the pandemic.

Although the government had to stamp out a Delta flare-up in June in Guangdong Province, authorities this time are dealing with a much larger spread. Since the current Delta outbreak started on July 21, the number of cases has risen to 483, more than the sum total of infections from the first five months of the year. By Tuesday afternoon, the virus had spread to 15 of the 31 provinces and autonomous regions in China.

“Once it reaches so many provinces, it’s very hard to mitigate,” said Chen Xi, an associate professor of public health at Yale University. “I think this would be surprising and shocking to the rest of the world. Such a powerful government has been breached by Delta. This will be a very important lesson — we cannot let our guard down.”