The former Valencia fullback will join Barca formally after Spain's London Olympics campaign.
Vilanova said: "We are very pleased with Jodi Alba's signing, it was a priority. The fact that he had a brilliant Euro campaign makes us think that we didn't make a mistake [in signing him].
"The fact that Jordi Alba is going to the Olympics doesn't disrupt our plans. He's young, and he was very excited to go to the Games, chances are he won't have another opportunity like this. The only thing I'm concerned about is that he might not get enough time to rest.
"Time will tell if he had enough time to rest, but I completely understand the national team manager wants to take the best possible team to the Games."