How can a vaccine change how people encounter diseases in their environment?

it can kill u nd paralize u or give u a new diease

Explanation:

well since twins have about the same dna they dont have one think in common which is the figer print. nobodys fingerprint is the same. if your using twin you would most likely get around the same results for both of them because of the genetics.. i hope this

this question does't support enough resioning to answer.