Even if it did say a "virgin," even if it said the boy would have been born from a man, the context goes on to describe a sign for King Ahaz.
It does not say, "A virgin will give birth to the second person of the Trinity. In English, derived from Latin, He will be named Jesus, He will take away the sins of the world. He it is the one that will show us that the Law was only there to show us how bad we are--We can't save ourselves. Our righteousness is like menstrual rags to God. (Yuck) So pass on the word for the next several hundred years. Look for his star in the East. In the meantime, don't worry about the two kings trying to invade you. I'll (the prophet now speaking as God) deal with them. But, later, you'll be taken captive anyway 'cause you never listen to me. I don't even know why I'm telling you all this. You'll just twist it around and not follow my Son anyway."
My problem is with a hard-line belief in a literal translation. For the Christian, obviously, Jesus is God, He is the only way, and everyone that doesn't believe in Him will be sent to hell. But that is based on a Christian New Testament that was tacked onto the Hebrew Bible.
However, what if you are a Jew and take a hard literal interpretation? The Law is forever, Messiah will bring peace--the first time, and the Messiah is not God, and God is not in three parts and whatever else. I don't know, but I'd like to know, and I'll stop there, because the Jews are doing a good job of speaking for themselves.