Chinese respiratory scientist Zhong Nanshan. (Photo: Xinhua)

The risk of COVID-19 reinfection within a year decreases significantly after having been infected with Omicron once, said China's renowned respiratory disease expert Zhong Nanshan on Thursday.

After the first infection, the newly produced antibodies are equivalent to an inoculation of vaccine, according to Zhong.

He made the remarks at a lecture on the fight against Omicron.

"The virus is highly contagious, and there's a high probability of infection," the expert said.

However, the later people get infected, the fewer painful symptoms they will suffer, and eventually, more infections will turn out to be asymptomatic carriers, Zhong said.

He also responded to online rumors that the variant in northern China is more pathogenic.

There is no essential difference between the main virus variants BF.7 in Beijing and BA.5.2 in the southern Chinese city of Guangzhou, Zhong said.