Coronavirus Vaccine in Taiwan - April 2021

I’m asking here as you guys seem generally much more informed about the vaccine situation than I am.

I am going with my kids to the States for 5 weeks starting on around June 7.

I need to make a choice of either:

(1) getting the AZ vaccine in Taiwan on May 13; or

(2) getting the Pfizer vaccine in the US on June 10.

If I get the Pfizer I can get both shots when I’m in the US and come back fully vaccinated. Also, if something goes wrong, I’d much rather be in the US medical system than Taiwan. However, if I get the AZ vaccine, I’ll at least have some protection before traveling, but I’m not sure if or when I can get my second jab.

Any thoughts or opinions?