The domestic COVID-19 epidemic is trending steadily downward, with the number of new daily infections dropping to under 600, a health official said on Friday.

Lei Zhenglong, deputy director of the National Health Commission's Bureau of Disease Prevention and Control, said that the daily count of new cases in Shanghai had been under 500 for four consecutive days.

"The overall situation is improving and coming under control," he said. "But compared with other cities, Shanghai is still at higher risk and should be careful of flare-ups at key facilities."

Meanwhile, Beijing also reported fewer new infections over the past two days, and eight of its 17 districts have reported no new infections. "But the regional spread of the virus is still possible and screening and isolating should be strengthened," he added.

As of Thursday, China had fully vaccinated over 89 percent of its population and nearly 775 million people had received a booster dose.

Among people aged 60 and above, 82.4 percent had been fully vaccinated and nearly 168 million had been given a booster shot, according to the commission.