Individual amino acid mutations previously reported in RSV resistant to fusion inhibitors (anti-F fusion inhibitors) were identified from those: i) fusion inhibitors co-crystallized with RSV fusion-stabilized recombinant F, ii) sequencing of RSV isolated after in vitro co-culture with host-cells and fusion-inhibitors, iii) sequencing of F from RSV isolated from naturally-infected RSV patients, and iv) emerging on F from GS5806-inhibitor-treated RSV-infected human volunteers.