The evolution of mobility is led by automated vehicles (AVs), as they are expected to decrease commute time and vehicle fuel consumption as well as significantly increase safety. One of the main limitations they face is motion sickness (MS), which could jeopardise AVs acceptance by the society. On one hand, AVs driving style is expected to be perceived more aggressive by AV users, which will cause more head and body motion. Hence, the control of the velocity and its minimisation are an efficient countermeasure of motion sickness mitigation in AVs. On the other hand, the excessive reduction of the velocity can significantly affect user's dissatisfaction due to longer journey time. Therefore, additional approaches of mitigating MS have to be considered without affecting journey time. In this direction, this paper proposes an active integrated seat suspension for both longitudinal and vertical isolation to minimise MS. The model is compared with a conventional passive seat design for vertical isolation only, and a passive integrated seat design. All the seat models are excited by vehicle responses obtained from IPG/CarMaker when a vehicle is driven over a real countryside road with Class B road roughness. The results illustrate more than 50% improvement in comfort and 20% more MS mitigation compared to the conventional passive seat.