Beijing no longer requires people to show a negative polymerase chain reaction (PCR) test for COVID-19 when entering public places such as supermarkets, commercial buildings and residential communities, local authorities said in a notice on Tuesday.

However, a negative COVID-19 test result within 48 hours is required to enter internet cafes, bars, karaoke, indoor gyms, elementary and middle schools, and the inpatient departments of hospitals, among others.

Negative test results are also no longer required for taking public transportation in the city starting Monday.

Major enterprises and organizers of large-scale events can determine their own requirements for COVID-19 tests, the notice said.

The city will also continue to provide free PCR tests to meet people's demands, according to the notice.

Beijing's latest policy adjustments come as many provinces and cities across the country are optimizing and refining their COVID-19 response to minimize its impact on people's livelihoods, with policies on COVID-19 tests, drug purchase and travel adjusted.

Experts: Omicron sub-variants less virulent

The Omicron sub-variants currently circulating in China are more transmissible, but cause less severe illnesses, according to experts.

Tang Xiaoping, head of Guangzhou Medical University, said over 90 percent of the infected cases in Guangzhou show no symptoms or only mild illnesses, and few of them develop pneumonia or even severe pneumonia.

So far, there have been more than 160,000 infected patients in the city in this wave, and there has been no death caused by COVID-19, Tang said, adding that only four cases have been diagnosed as severe, all because of their underlying diseases.

"Therefore, I think the virulence of the Omicron sub-variants is obviously weakening, which is very close to seasonal flu. It's now a disease that can be prevented, controlled and treated," he told China Media Group.

Tang's views were echoed by Zhang Zhongde, head of Guangdong Provincial Hospital of Traditional Chinese Medicine, who's also a member of the national expert group on COVID-19 treatment.

He said Omicron infections cause symptoms very similar to flu, such as fever, headache, sore throat and cough. Some patients suffer body aches and diarrhea, but they are very rare, he added.

He also said that the majority of the patients see their symptoms alleviated in 12 to 24 hours after taking medicines, and asymptomatic and mild cases usually get negative PCR test results in five to seven days.