For most countries, the peak of Covid-19 cases in China would register little more than an oversight on the graph.
But the 184 infections detected in Nanjing city over the past 10 days will test whether the country’s zero-tolerance approach, which has quickly dealt with previous outbreaks, can contain the highly transmissible delta variant.
The outbreak is said to have started in Nanjing, a city of more than 9 million people, about 150 miles west of Shanghai.
On July 20, nine cleaners at Nanjing Lukou International Airport tested positive for the virus after cleaning a plane from Russia, according to state media. Infections have now been recorded in five different provinces, including Beijing, and local health officials have identified the strain as the delta variant.
Authorities in Nanjing are now on “high alert” and plan to test all residents of the city, having already passed 1.9 million people in one day, Xinhua News Agency reported on Thursday.
China crushed previous peaks with locks, quarantines and tight controls on international travel.
After the initial Covid outbreak, which was first recorded in Wuhan in December 2019, outbreaks in China have been relatively minor by international standards and against the backdrop of China’s 1.4 billion people .
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The United States recorded 202.4 infections for every million people on Thursday, according to Johns Hopkins University. The same figure for China was 0.04.
But daily cases in China are now at their highest level since January, when tens of millions of people were taken into custody as authorities struggled to suppress cases centered around Hebei province.
The current outbreak has drawn a strong rebuke from the Central Commission for Discipline Inspection, a high-level disciplinary arm of the Communist Party of China. He said Nanjing Airport did not separate cleaners for international and domestic flights, and criticized airport management for what they called lax to prevent further spread.
The increase in cases has also raised questions about the effectiveness of Chinese vaccines against Covid, manufactured by the public company Sinopharm and the private company Sinovac.
Other countries that have used these Chinese vaccines have experienced waves of infections. More than 30 Indonesian health workers have died after receiving two doses of Sinovac.
And Chile reintroduced restrictions after a wave of the delta variant ravaged its population, 70% of whom were fully vaccinated, mostly with Sinovac.
Some experts say other factors may have been involved, including people who mix too quickly after their first dose in Chile. Others believe that Chinese vaccines have shown good protection against serious illnesses.
And it is possible, although rare, for people to catch Covid and become seriously ill after two doses of any vaccine.
China has not released clinical trial results or actual data that would be needed to assess the effectiveness of vaccines against different variants. This makes peer review difficult.
Sinopharm and Sinovac say their shots provide sufficient protection against the delta. And people in China who have been fully vaccinated have mostly exhibited mild symptoms during the current crop of infections, state media said.
The rest of the world weary of the pandemic has seen life return to normal for many Chinese, with images of crowded pool parties and bustling theme parks in stark contrast to lockdowns in the West.
The country and its government are now hopeful that its current epidemics will not turn time back to the gloomy days of early 2020.