One of them is a 31-year-old man who flew in from South Korea on September 2. He had received two doses of the Sinovac vaccine in Pakistan in June and July.
The other patient is a 25-year-old man who came from Serbia on September 4. He tested positive while undergoing quarantine at the Metropark Hotel Kowloon in Ho Min Tin.
He had been double jabbed with the Sinopharm vaccine in Serbia in March and April.
Neither of them showed any symptoms.
Authorities also reported fewer than five preliminary positive cases.
In total, Hong Kong has reported 12,131 Covid-19 cases since the start of the pandemic.