The decision comes after hundreds of medical workers caught Covid despite being fully vaccinated with Sinovac.
Instead of two Sinovac shots, people will now receive the AstraZeneca vaccine after their first Sinovac shot.
Health workers already fully vaccinated with Sinovac will also receive a third booster from a different vaccine.
This can be either the AstraZeneca vaccine, or an mRNA vaccine like Pfizer/BioNTech. This third dose will be given three to four weeks after their second Sinovac jab, said the country's National Infectious Disease Committee on Monday.