Horner: It isn’t over yet
"The cards have definitely fallen in favor of Brawn so far," Horner told Autosport. "Perhaps KERS cars have impacted our races (been in our way).
"We're just looking forward to having a straight fight in clean air with the Brawns. Other than in China, we haven't really gone head-to-head with them."
Jenson Button has a 28-point lead over third-placed Vettel while Red Bull are 43.5 points behind Brawn GP in the Constructors' Championship.
Horner, though, is confident the Milton Keynes-based outfit can catch Brawn once they've added "some great developments" to the RB5.
"Brawn has a huge lead in the constructors' and a significant lead in the drivers'," he said. "We're going to focus on every race as it comes.
"We believe that the next couple of races should play to the strengths of our car and we have some great development in the pipeline.
"Jenson is only four points off a maximum score, which is a remarkable achievement but things can change very quickly. We're going to take every race as it comes and the Championship will take care of itself."