Omicron variants dominate China's outbreak

The more virulent Delta strain of COVID-19 is not currently circulating in China according to epidemiological data, experts said.

X-ray images of the whited-out lungs of recently infected patients have been circulating on Chinese social media lately, prompting speculation that more severe strains of COVID-19 are spreading in the country.

Xu Wenbo, the director of the National Institute for Viral Disease Control and Prevention of the Chinese Center for Disease Control and Prevention, said real-time epidemiological data show no trace of the Delta strain in the country, nor of a recombinant of the Delta and Omicron strains.

Since early December, scientists have detected nine strains, all of which are variants of Omicron, he told Xinhua News Agency.

Xu said that the BA.5.2 and BF.7 strains are the dominant variants in China, accounting for over 80 percent of cases. However, 31 Omicron strains are present on the Chinese mainland, including the BQ.1 and XBB variants that are driving up cases in other countries.

Jiao Yahui, director of the National Health Commission's Bureau of Medical Administration, said that whited-out lungs is a sign of severe pneumonia that could result in breathing difficulties and low blood oxygen levels.

However, this is not a symptom of the original COVID-19 viral strain or of vaccinations, she said, adding the current variants in circulation are from the Omicron family.

Wang Guiqiang, director of the Department of Infectious Diseases at the Peking University First Hospital, said that for most people who are not immune compromised, the chance of reinfection by the same strain of virus is extremely low.

He added that even if reinfection were to occur, symptoms would most likely be mild, but if a new strain of virus with greater ability to evade immunity were to emerge, then there is a chance of reinfection, Wang said.

"Therefore, people should still protect themselves after this wave is over," he said.