China will continue to quarantine travelers arriving from overseas and will not exempt vaccinated people from prevention and control measures for the moment, Feng Zijian, deputy director of the Chinese Center for Disease Control and Prevention, said at a news conference on Sunday.

To prevent imported cases of COVID-19, Feng said China will continue to strictly implement centralized isolation and conduct nucleic acid tests on people entering the country, including those vaccinated.

China also will issue different policies on visa issuance and the number of flights and arrivals according to the level of vaccination and pandemic control situation in different countries. At the same time, the country will keep an eye on the progress of the "vaccine passport" internationally and adjust preventive measures when the domestic population has reached a high level of immune protection, he said.

Feng said the pandemic is still ongoing and national vaccination rates are still relatively low to achieve a high level of herd immunity, making it still risky that the entry of people or goods from overseas will bring transmission within the border.

In addition, a person who has already been infected or vaccinated does not mean a zero possibility of reinfection, he added.

He noted that all types of current vaccines have proved to be very effective in preventing severe cases but not as effective as in preventing infections or minor illness, especially considering the emergence of several mutated variants outside the country that might influence the effectiveness of the vaccine.

"Taking these factors into account, the country will continue to adhere to strict measures to prevent imported cases and domestic reoccurrence and will adjust some of the measures in an orderly manner, according to the global pandemic and vaccination situation," he added.