Have the HK government said they are only using the sinoVaccine?
By comparison, Australia hedged its bets and ordered supplies from 3 or 4 sources, the Pfizer, the AstraZeneca, the Novovax and i think also a Covax vaccine, but that’s not as well developed.
It seems odd that HK being as well developed and relatively affluent from a GDP perspective, would not have a number of suppliers.