If the vaccum pack is still sealed they'll be fine. If open and they look and smell "dusty" then probably best chuck them unless you're going to make a "heritage" recipe which often calls for old hops. Styrians are often used at the end of the boil and at flameoiut so, since it's the alpha acid content that tends to deteriorate with age, you might want to use some fresher hops for bittering, but, frankly, in my experience it doesn't make a great deal of difference as long as the hops look and smell sound when you open the pack- which they almost certainly will.