Omicron Photo: VCG

No Delta variant has been found to be prevalent in China, and no restructuring of the Delta or Omicron variants has been found either, experts said on Tuesday, in response to public queries over whether there are new COVID-19 variants being detected in the country. 

"Since the beginning of December, nine subvariants of the virus circulating have been detected in China, all of which belong to the Omicron strain," Xu Wenbo, director of the national institute for viral disease control and prevention with Chinese Center for Disease Control and Prevention (China CDC), said in an interview with the Xinhua News Agency on Tuesday.

Since the beginning of December, the China CDC has completed the whole genome sequencing of 1,142 cases through a sampling survey and found that the Omicron subvariants BA.5.2 and BF.7 were the dominant strains, accounting for more than 80 percent of the total, said Xu. There are also seven other subvariants of Omicron circulating.

No genomic mutation was found in these subvariants, which were all imported, according to Xu. In December, a total of 31 Omicron subvariants were found to have been imported into China, including BQ.1, XBB and other subvariants that spread rapidly overseas, said Xu.

Renowned Chinese epidemiologist Li Lanjuan also said that the Omicron variant is the dominant strain prevalent in China. "We did not detect [the Delta variant], and the Delta variant has been replaced [by the Omicron]," Li told the China Business Journal on Tuesday.

Some COVID-19 patients were found to have pneumonia or their CT scans showed they had "white lungs" recently. Now the so-called "white lungs" have nothing to do with the original strain or vaccination, and Omicron is still the dominant strain, Jiao Yahui, a senior official with the National Health Commission, said at Tuesday's press briefing.

Beijing CDC researcher Pan Yang said the virus subvariants circulating in Beijing are the Omicron subvariants BF.7 and BA.5.2. No XBB, BQ.1 or other variants were found in Beijing communities, and non-Omicron variants such as the original strain and Delta strain were not detected, said Pan, according to Beijing Daily.

Wuhan, Central China's Hubei Province, has carried out sampling and monitoring in two sentinel hospitals once a week, collecting 20 throat swab samples each time. In December, the samples were increased to 40 each time, and Wuhan Jinyintan Hospital was added as a sampling sentinel hospital this week, according to the Hubei authorities on Tuesday.

The monitoring data indicate that Omicron BA.5.2 is still the variant circulating in Wuhan. Since October, all the viruses detected in the collected samples were BA.5.2 variant strains, and no other types of strains were found, Yang Xiaobing, an official with the Wuhan CDC, said on Tuesday. 

As for the public's question over whether people will be reinfected, Wang Guiqiang, director of the infectious diseases department at Peking University First Hospital, told Xinhua that for the vast majority of people with normal immunity, there will be effective immune antibodies for half a year, and the probability of reinfection from the same strain is very low. Even if they are infected, there will be no serious symptoms.

However, reinfection may occur if a new mutant or subvariant shows strong immune escape ability, so Wang suggested the public still be cautious after this wave of outbreaks.

Elderly people, especially those who did not take vaccinations, should take oral antiviral small-molecule drugs as soon as possible if they are infected, normally within five days, according to Wang.

Global Times