China has recently announced that COVID-19 will be managed as a Category B disease, and lifted quarantine for inbound passengers. But some countries have imposed restrictions on Chinese travelers.

Shen Ning, an expert in respiratory disease from Peking University Third Hospital, said it's necessary to tighten monitoring but not to limit people's travel.

Shen said that new variants may easily come out and mutate with more changes, but population mobility is a must in the future. She stressed both China or other countries should monitor well.

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