It depends what you mean by "disadvantage".
Fellowship programs won't care that you graduated last year. Lots of people decide to take a gap year or two for all sorts of reasons -- their partner needs to finish their school / residency / job and can't move, they want to pay off some loans, they want to do a research or a chief year, or they want to do some locums work and travel. Or, as in your case, they applied and didn't get a spot. Most fellowships won't care at all.
But, just like the biggest risk factor for having an MI is prior having an MI, a big risk factor for not matching is not matching. If you didn't match in this last season, you need to re-evaluate your options. Try to fix whatever hole there was in your app, pick different programs, and try again. But I expect you'd find that the overall match rate of those who re-apply is lower than first time applicants -- simply because the re-applicants are probably less competitive overall (hence why they are re-applying).