World Vector Issue?

I am trying to rotate the world, but when I supply values to the vector parameter I see no change in the rendered output.

How do you rotate the world around the camera?

<background name="World">
	<environment_texture name="hdri" filename="./maps/HDRI-Sunny.hdr" vector="90.0 0.0 0.0" />
	<background name="bg" strength="1.0" color="1.0 1.0 1.0" />
	<connect from="hdri color" to="bg color" />
	<connect from="bg background" to="output surface" />