In a method for manufacturing a wind turbine blade half shell, a preformed and cured aerodynamic blade shell member 42 of a fibre reinforced resin is provided. A primarily uniaxial fibre material 66 comprising carbon fibre is laid up on a longitudinal inner area 50 of the preformed shell member 42 and then infused with a resin by vacuum-assisted resin transfer moulding (VARTM), where a longitudinal resin inlet channel 80,82 is arranged on a first lateral side 46 and a vacuum channel 86,88 is arranged on a second lateral side 48 of the laid-up fibre material, and the resin is infused in transverse direction from the first to the second lateral side 46,48.