If you are going to give an adult HepB vaccine and draw the screening hepatitis B triple panel at the same visit, does it matter which one you do first?

Draw the blood for screening first. It is possible to detect HBsAg from the HepB vaccine in serologic tests up to 18 days after vaccination, so CDC recommends obtaining blood for the screening triple panel before administering the first dose of vaccine to avoid any chance of a false positive HBsAg result. If the triple panel screening test needs to be done later, wait one month after administration of the most recent dose of HepB vaccine.