[TomGuy]

Those blank card images are all over the net. Just put 'COVID card' or 'COVID CDC card' or similar in your favorite search engine and select 'images'.

Blanks are being sold on Amazon - $7.29 Prime for 4x3 CDC Vaccination cards:

2-pack blank CDC Vaccination Cards

[WhattheDickens?]

The Amazon products are NOT blank vaccination cards! They are plastic vaccination card protectors.

[Oystir]

That’s an $8 ziplock bag