(Reuters) -Moderna on Thursday reported a surprise fourth-quarter profit, helped by cost cutting and some deferred payments, and the vaccine maker set out a commercial roadmap for its experimental respiratory syncytial virus (RSV) shot. Moderna posted a profit of $217 million, or 55 cents a share, for the quarter. Moderna Chief Financial Officer James Mock in an interview said the company beat its own forecast because of unexpected deferred revenue of $600 million and cost savings of around $300 million created by the company's effort to adjust its manufacturing output last year.