TAIPEI (Taiwan News) — Approximately 550,000 Taiwanese and foreign residents who have received a first dose of the AstraZeneca (AZ) COVID-19 vaccine will be able to receive a Pfizer-BioNTech (BNT) shot as soon as November.

In its 13th round of inoculations, Central Epidemic Command Center (CECC) will allow for the mixing of the AZ and BNT vaccines. The round is anticipated to start as early as November and will be open to all age groups who were eligible for the AZ jab.

CECC Spokesperson Chuang Jen-hsiang (莊人祥) on Friday (Oct. 22) said that according to estimates, if all 12 rounds of vaccines are administered as scheduled, about 550,000 doses of the BNT vaccine will be available for residents who received their first dose of the AZ vaccine at least 10 weeks ago. If lots of people miss their appointments for BNT shots before then, even more doses will be made available.

Health Minister and CECC head Chen Shih-chung (陳時中) said the BNT shots should be available for AZ recipients by November. Regarding the registration to indicate a preference for BNT, due to a slight modification of the vaccine registration and reservation platform, Chen said the new application policies will be announced in the next two days.

There are concerns that a lot of people will drop their AZ appointments and wait for a different vaccine brand. In response, Chen said that although there are international reports the AZ jab mixed with mRNA shots can induce more antibodies, some experts have pointed out that different types of vaccines will trigger the body to produce different antibodies, which may increase the risk of adverse reactions.

He said that although the probability is low, different vaccines have their advantages and the CECC will provide a certain amount of each as much as possible for the public to choose from.