The Tokyo Olympics have proven that it is possible to "keep the pandemic at bay" and lessons learned from the games held under unusual settings will be shared with the world, a leading health adviser to the sporting event said Saturday.

Brian McCloskey, chair of the Independent Expert Panel for the Olympics, said basic anti-COVID-19 measures and a good testing scheme are what have made a "safe and secure" games possible, with the number of people related to the event who tested positive for the disease since the start of July totaling about 400.

"We have shown it is possible to keep the pandemic at bay. And that is a very important lesson from Tokyo to the rest of the world," McCloskey said during a press briefing.

The organizing committee of the games has said over 600,000 tests have been carried out, with the cumulative total of those COVID-19 cases standing at 404 after another 22 people were added on Saturday.

Most of the positive cases involved workers who were residents of Japan. Based on the organizers' "playbook" rules aimed at controlling infections, athletes, for instance, were required to undergo testing every day in principle.

As for the daily count, released Saturday, no athletes tested positive for the second straight day. Of the 22, 13 are contractors, four are games-related officials, two are members of the media, two are employees of the organizing committee and one is a volunteer.

Of the total, 16 are residents of Japan, the committee said, adding that one person from overseas who was staying in the athletes' village is among those who have tested positive.

Compared with the situation outside of the village, where Olympic officials have said athletes live in a "parallel world" with strict anti-COVID-19 measures, the number of infections among people linked to the games has stayed relatively low.

The total number of coronavirus cases in Japan has topped 1 million while the 17-day Olympics are nearing their close on Sunday.

"What is important is the core message from the (World Health Organization) and other agencies that the way you manage this pandemic is through basic public health measures and a good testing regime," McCloskey said.

"We've proved that works," he said, adding that collected data will be provided to the rest of the world to cope with the pandemic.

The health adviser dismissed concerns among some health and other experts in Japan that the Olympics, held when Tokyo and some other prefectures are placed under a state of emergency, have reduced the public's guard against COVID-19 by creating a festive mood.

"There's no evidence to suggest that has happened," he said. "It is important to remember one of the fundamental principles of epidemiology is to separate association and causation."

"Because things happened at the same time that doesn't mean that one caused the other."

That view was echoed by IOC chief Thomas Bach, who said Friday that the Tokyo Olympics "far exceeded" his expectations as anti-virus measures worked and the performance of the athletes moved him.