Relying on infection with the Omicron strain to develop immunity to COVID-19 is a dangerous and flawed choice, a health expert said on Friday.

Wang Huaqing, chief epidemiologist at the Chinese Center for Disease Control and Prevention, said that even though an infected person will gain immunity against the virus in theory, this is not the right approach for China.

"The Omicron strain can result in severe illness and death, especially among people with chronic illnesses and the elderly," he said during a news briefing. "So the unvaccinated will be at risk."

Wang added that COVID-19 vaccines in use have proven to be highly effective in preventing severe illness and death, but the level of immunity developed through infection is uncertain.

He said that recent studies have shown that the number of antibodies triggered by the Omicron strain in unvaccinated people is lower than in those who are vaccinated, suggesting that natural immunity against different strains may be limited.