No, but there are talks about making this better that it will allow curation rewards at the point of the new vote. So far it isn't scheduled to be in a specific hard fork but would be a better behavior if approved. This will allow you to get curation rewards even if changing your vote, but you lose your original position.
The reason for the loss of curation rewards is to prevent a user from voting a minimum amount on many posts to lock a curation position then changing it to a larger vote if a post starts to do well.