The Chinese Center for Disease Control and Prevention on Wednesday reported that it recorded 1,968 severe COVID-19 infections and 239 deaths on the Chinese mainland last month, compared with 2,777 severe cases and 164 related deaths recorded in May.

Last week, the proportion of the XBB strain and its substrains increased to 96.2 percent, the center said.

Among the deaths, two were due to respiratory failure, while the rest were caused by a combination of underlying diseases and COVID-19 infections, it said.

The number of fever clinics on the mainland decreased from 288,000 to 164,000 in June.

Last week, the proportion of symptomatic COVID-19 cases made up 4.4 percent of all hospital visits, down from 5.5 percent during the 22nd week of this year (May 29 to June 4), the center noted.

The number of positive symptomatic cases decreased from 42.5 percent during the 21st week of this year (May 22 to May 28) to 15.4 percent last week (June 26 to July 2).

The center added that 12,431 locally transmitted cases with valid genome sequences were reported last month. All of them were Omicron variant strains, covering 141 evolutionary branches.

The main circulating strains were the XBB series variant strains. The top three proportions were XBB.1.9 and its substrains, XBB.1.16 and its substrains, and XBB.1.22 and its substrains.

The proportion of XBB and its substrains gradually increased from 94.7 percent during the 22nd week to 96.2 percent last week.