Member States shall take the necessary measures to ensure the preservation of vested pension rights for membrs of a supplementary pension scheme in respect of whom contributions are no longer being made to that scheme as a consequence of their moving from one Member State to another, to the same extent as for members in respect of whom contributions are no longer being made but who remain within the same Member State. This Article shall also apply to other persons holding entitlement under the rules of the supplementary pension scheme in question.