A medical worker collects a throat swab from a resident in a nucleic acid testing unit at a sampling site of Beijing Anzhen Hospital, Beijing, capital of China, June 24, 2020. (Xinhua/Ren Chao)

Global monitoring of the novel coronavirus shows that the virus has not mutated, which is a good sign for the research and development ofvaccines, according to Wu Zunyou, chief epidemiologist at the Chinese Center for Disease Control and Prevention.

Wu made the remarks in an interview with CCTV on Monday evening, during which he also picked up questions regarding pidemic control measures in Beijing and the pandemic situation around the world.

The number of confirmed cases in Beijing might go down to zero in around one week as the cases found recently were mostly people who had already been quarantined and put under observation, whose onset period ranged from four to 13 days.

However, Wu also pointed out that the government cannot loosen its epidemic prevention and control work and needs to see it through to the end.

As the number of COVID-19 patients surpassed 10 million and deaths topped 500,000 around the world, Wu said that the number has not yet peaked and will continue to soar in the near future.

The time it takes for the number to increase from 10 million to 20 million will be even shorter, as most countries have not made effective efforts to control the epidemic except China and a few others, he said.

"The situation in some countries has gone out of control and is getting worse and worse," he warned.