MAVS and viral infectious disease: IPS-1 was chosen as adjuvant candidate since the retinoic acid inducible gene I (RIG-I)-IPS-1 pathway plays an important role in innate immune sensing of viral infections including RSV (48–50) and the subsequent activation of adaptive immune responses (51, 52) as exploited by the co-application of RIG-I agonists in vaccination settings (53, 54).