Vahaamahina replaces Jocelino Suta, who was on the bench for Saturday's 23-13 loss to England, and Medard comes in for left wing Benjamin Fall.
France were beaten 23-18 by Italy in their opening match before losing 16-6 at home to defending champions Wales.
Backs - Maxime Machenaud, Morgan Parra, Frederic Michalak, Francois Trinh-Duc, Mathieu Bastareaud, Vincent Clerc, Wesley Fofana, Florian Fritz, Yoann Huget, Maxime Medard.
Forwards - Vincent Debaty, Thomas Domingo, Benjamin Kayser, Dimitri Szarzewski, Luc Ducalcon, Nicolas Mas, Yoann Maestri, Christophe Samson, Antonie Claassen, Thierry Dusautoir (captain), Yannick Nyanga, Louis Picamoles, Sebastien Vahaamahina.
- Sports & Recreation
- Jocelino Suta
- Wesley Fofana
- Morgan Parra
- Mathieu Bastareaud