On December 23, the Central Epidemic Command Center (CECC) reported that considering that some individuals have volunteered to participate in clinical trial programs of COVID-19 vaccine candidates, the Advisory Committee on Immunization Practices (ACIP) at the Ministry of Health and Welfare recommended that such individuals can receive another COVID-19 vaccine approved in Taiwan 28 days after their last dose of the COVID-19 vaccine candidate, if they wish to receive further vaccination, after discussing it with the research team of the clinical trial and a physician's assessment. The ACIP made the recommendations after evaluating vaccination policies in other countries.