China’s abrupt move to dismantle its strict Covid-19 regime, which unleashed the virus onto its 1.4 billion residents, could have led to nearly 2 million excess deaths in the following two months, a new US study shows.

The study by the federally funded Fred Hutchinson Cancer Center in Seattle was taken from a sample of mortality data published by some universities in China and internet searches.

It found an estimated 1.87 million excess deaths from all causes occurred among people over 30 years of age between December 2022 and January 2023, and were observed in all provinces in mainland China except Tibet.

China’s decision last December to end the three-year zero-Covid policy, which included mass-testing and stringent and persistent quarantine lockdowns, led to a massive surge in hospitalisations and deaths that health experts say were largely unreported by the government.

The study, published on Thursday in JAMA Network Open, said the number of excess deaths far exceeded official Chinese government estimates in January that 60,000 people with Covid-19 had died in hospital since the zero-Covid policy was abandoned a month earlier.

In the study, researchers performed statistical analysis using information from published obituaries and data from searches on Baidu, a popular Chinese internet search engine.

“Our study of excess deaths related to the lifting of the zero-Covid policy in China sets an empirically derived benchmark estimate. These findings are important for understanding how the sudden propagation of Covid-19 across a population may impact population mortality,” researchers wrote.

China’s National Health Commission did not immediately respond to a request for comment on the report.

Global health experts repeatedly called on China to reveal more data as reports of rising hospitalisations and deaths started to surface, and especially as the threat of new variants became a concern.

China stopped reporting official daily death results at the end of 2022. The World Health Organization says there have been 121,628 Covid deaths in China, out of a total global toll of almost 7 million.

In a rare move, one Chinese province briefly published data on its website in July showing cremations jumped 70% in the first quarter of this year that was later taken down.

In February, China’s top leaders declared a “decisive victory” over Covid.

But the virus is still making its rounds in the country and on Thursday, Beijing health officials said Covid is still the number one infectious disease in the capital, according to Chinese state media.

Officials cited a new Omicron variant, called EG.5 or “Eris” nicknamed after the Greek Goddess of strife and discord, as the current dominant strain across China.

“The National Bureau of Disease Control and Prevention said the proportion of the new variant EG.5 increased from 0.6% in April to 71.6% in August, becoming the dominant strain in most provinces in China,” the Global Times reported.