The Uruguay left-back signed for Roma from Palmeiras in 2021 and has appeared 29 times in Serie A.
But Vina has been limited to just 54 league minutes under Jose Mourinho this season and has left for Bournemouth at least until the end of the campaign.
The 25 year-old is reportedly set to be joined at his new club by Sassuolo midfielder Hamed Traore and Dynamo Kyiv defender Ilya Zabarnyi on Tuesday's transfer deadline day.
Bournemouth appear to have failed in a bid for Nicolo Zaniolo had have already brought in Dango Ouattara and Antoine Semenyo.
Meanwhile, Roma is said to be close to signing Diego Llorente from Leeds United.
