The mark will be a visual mark that can be seen instantly. That said, there is nothing that says the mark can’t include a subdermal chip.
Next Generation injections:
1/7/21
“World first COVID-19 smart vaccine patch”
https://www.healtheuropa.eu/world-first-covid-19-smart-vaccine-patch/104768/?fbclid=IwAR0J_rKnQC5TNomvtTetWvr0lPIuHWv87akLI3Mw7xGzouIueQOYaBV346g