Does it make a difference to a provider if the guy has had a vasectomy?  Are you more comfortable if you know this?  Would you trust him to be truthful?  Does it matter at all?

A vasectomy doesn't protect from STDs (See question 8 in the link below).

Question:

Will a vasectomy protect me from a STD?

No. A vasectomy cannot protect you from a sexually transmitted disease, including AIDS.

Condoms are still the best protection against these diseases.