After Panda Update, Scraper Sites Still Taking Top Positions

I publish an original news post and after an hour or more I get links from relevant sites.The related posts with backlinks to my post (on these relevant sites) get on the top of Google SERPS and my page is somewhere around #5.After a couple of hours, a couple of scraper sites take over my position and I’m on the 2nd, 3rd page or simply nowhere.