China said Wednesday that not a single person had died of Covid-19 the previous day, after changing the criteria for recording virus deaths to mean most are no longer counted.

China had recorded a total of seven deaths — all in Beijing — since the decision to lift the zero-Covid policy, but removed one death from its official tally Wednesday.

The removal followed a government announcement that only those who had directly died of respiratory failure caused by the virus would be counted under Covid death statistics.

Previously, people who died of an illness while infected with the virus were counted as a Covid death. This way of recording Covid deaths accounts for huge numbers of fatalities in other countries.

"At present after being infected with the Omicron variant, the main cause of death remains underlying diseases," Wang Guiqiang of Peking University First Hospital told a press conference of the National Health Commission (NHC) on Tuesday.

"Old people have other underlying conditions, only a very small number die directly of respiratory failure caused by infection with Covid," he said.

And one expert told AFP that because the prevalant Omicron variant does not affect the lungs as much as other strains of Covid-19, the changing definition will mean a great many more cases will now go unrecorded.

"The definition that focuses on respiratory failure (which develops when the lungs can't get enough oxygen into the blood) will miss a large number of Covid deaths," Yanzhong Huang, a senior fellow for global health at the New York-based Council on Foreign Relations, said.

"The new definition is a reversal of the international norm adopted since mid-April during the Shanghai outbreak, which counts a Covid death as anyone who died with Covid," he added.