On November 17, the Central Epidemic Command Center (CECC) announced that the COVID-19 Vaccination Registration and Reservation system (https://1922.gov.tw/) will be open from 10 a.m. to 4 p.m. on November 18 for individuals aged 18 and older who have received a first dose of AstraZeneca (AZ) to register their willingness to mix and match vaccine brands; eligible individuals wishing to opt for the mix-and-match approach can choose the Pfizer-BioNTech vaccine, the Moderna vaccine, or both vaccines as their preference for their second shot.