By Ted Hesson and David Shepardson WASHINGTON (Reuters) -U.S. health officials are planning to end a sweeping, pandemic-related expulsion policy that has effectively closed down the U.S. asylum system at the border with Mexico by May 23, a U.S. official familiar with the matter told Reuters, adding that the decision had not yet been finalized. A second U.S. official told Reuters the Centers for Disease Control and Prevention (CDC) is set to lift the order, known as Title 42, as early as Thursday with a delayed effective date of a month or longer to give U.S. border authorities time to prepare …