80% of people in China caught Covid since early December, say officials

About 80% of China’s population has been infected with Covid-19 since restrictions were lifted in early December, Chinese health authorities have said.

The figure, which equates to about 1.2 billion people, prompted some pandemic experts to estimate that more than 1 million may have already died, far more than the government’s official tally of about 72,000.

A wave of Omicron cases engulfed China after the government abruptly ended its zero-Covid policy last December, lifting restrictions shortly before the start of the lunar new year and Spring festival. On Saturday, China’s Center for Disease Control and Prevention (CDC) said about 80% of the country’s 1.41 billion people had been infected in this wave.

In the week leading up to the lunar new year, the CDC reported 12,658 deaths, adding to the official pandemic toll of almost 60,000, but one which most observers believe is far below the real figure. Until a dramatically increased update earlier this month, the official toll from this wave was reported as being below 60 deaths.

Skyrocketing case numbers in December quickly overwhelmed data collection processes. Coupled with a narrow definition of a Covid-attributed death, official tallies soon appeared far below the reality on the ground, and the government was accused of lacking data transparency.

Beijing rejected the accusation and defended both the zero-Covid policy and its sudden dismantling. Some health officials have acknowledged the data discrepancies but said now was the time to focus on the health response.

The data and transparency concerns have left experts looking for other ways to estimate the impact of the outbreak.

Prof Robert Booy, an infectious diseases paediatrician at the University of Sydney, said the death toll was likely to be between 600,000 and 1 million. Booy, and other experts who spoke to the Guardian, said the virus was probably already spreading far more widely than acknowledged prior to the lifting of restrictions.

“China might have dropped its zero-Covid policy in the first week of December, but they were probably already flailing and failing,” he said.

“In 2022, China lost population for the first time since the Great Leap Forward – a drop of 850,000 people. They’re going to lose at least that number in the coming weeks of Covid, mostly of very old people who haven’t been fully vaccinated.”

Dr Xi Chen, associate professor of health policy and economics at Yale, said no one had good enough data to accurately gauge China’s death toll, but making conservative assumptions that it was suffering the lowest case fatality rate of 0.11%, would suggest that about 1.23 million people had died.

“Of course, this assumes China has healthcare resources like South Korea and New Zealand do,” he added.

Prof Antoine Flahault, director of the institute of global health at the University of Geneva, based his estimate on excess mortality rates – the number of deaths from all causes that are beyond the average – of other countries that have already passed their major first Covid waves.

“If you take Hong Kong, you have nowadays an excess mortality … which is roughly 2,000 deaths per million. If you convert that rate to China, you get to a bit below 3 million deaths,” he said, also adding the caveat that China’s health system was not as consistently developed as systems in other places, including Hong Kong.

“If you take Brazil, the figure is close to 4,000 per million, so it’s double.”

Associate Prof James Trauer, head of the epidemiological modelling unit at Monash University, cautioned against making estimates so early in the wave, noting that it wasn’t clear how China’s CDC was able to produce the 80% figure, given the issues with data collection.

The CDC notice had said that holiday travel may further spread the virus in the short term, but that because so many were already infected, “the possibility of a large-scale epidemic rebound or a second wave of epidemics across the country is very small”.

Trauer warned against thinking that an Omicron wave brought high levels of herd immunity.

“In Australia we had a huge first wave with B.A.1 last summer, and then the second wave with B.A.2 came straight on the heels of it within a couple of months. I don’t think they should assume that because numbers are coming down that they don’t have to worry,” he said.

“Probably the most important thing from the Chinese perspective at the moment is to manage the epidemic better and increase the resources to treat the people getting sick.”