query

[Simon Gosling]

hi, after gaining entry to USA i was issued with details to go to a civil doctor to get flu jab and TB skin test,this was a relatively straight forward process and i came out with flying colours,however after all paperwork was countersigned and signed etc,he gave me a sealed envelope,what do i have to do with this,is there a procedure that i need to follow now....can anyone give me a hint?

appreciate it