Japan's top COVID-19 adviser Shigeru Omi on Wednesday warned against hastily easing anti-pandemic restrictions on people's lives and called for relaxing measures only after the state of emergency is lifted.

His remarks came as the government seeks to ease restrictions around November, when it aims to complete vaccinating all people who wish to be inoculated. The plan includes letting eateries provide alcohol and allowing people to travel across prefectural borders and hold big events with more attendees even if the state of emergency is still in force.

Shigeru Omi, chairman of a government subcommittee on the coronavirus response, speaks during a House of Representatives committee session in Tokyo on Sept. 15, 2021. (Kyodo)

"Even though the vaccination rate has risen, there will certainly be a rebound if we suddenly ease restrictions," Omi told the House of Representatives' health committee.

"I believe the path we should take is to gradually lift them after the state of emergency expires and the number of infections comes down to a certain level," Omi added.

With the medical system still under strain from an influx of COVID-19 patients, much of Japan will remain under a state of emergency through Sept. 30. Government data shows slightly over half of Japan's population has been fully vaccinated so far against COVID-19.

Looking ahead, Omi warned that the fight against the new virus is expected to last for a long time. "It may take about two to three years until the public no longer has to worry about COVID-19, like the influenza in which we have vaccines and medications," he said.

In the same committee meeting, health minister Norihisa Tamura said the government remains on guard with an eye out for a potential "sixth wave" of infections.

"It is a fact that the number of new coronavirus cases is rapidly decreasing on a national level," Tamura said, but added that he worries about more people interacting with others in line with children going back to school this month, a drop in ventilation during winter, and an increase in socializing toward the yearend.

Over 60 percent of the population is expected to be fully vaccinated by the end of September, bringing Japan on a par with major European countries such as Britain and France, according to the government.

Japan initially lagged far behind other major economies in inoculating its population. Facing criticism, the government has made relatively fast progress since, setting up mass inoculation sites and offering workplace vaccinations.

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