We all issue updates to our handbooks. Perhaps they come in the form of a new or revised policy. Perhaps we issue an entirely new edition of the book. Anytime you issue new policies and/or a new book, you should also issue a new Handbook Receipt. If you expect to hold your employees accountable for adhering to the content of your book, then be sure their accountability is documented with a receipt signed and dated AFTER the last update was issued, not before.
Be sure to provide all employees with a Receipt for the book, which they must sign and return to you for placement in their employee file. Further, be sure that the receipt clearly states that by signing that document they acknowledge receipt of the book AND that they have read it thoroughly. This is far more powerful than simply stating that they agree to read it.