Google's John Mueller said it is fine to publish some content in both PDF and HTML formats. He said both "can be shown independently in the search results." If Google sees them as duplicates, in some cases, Google may just show the HTML version in its search results. He posted this Q&A...
New Adobe PDF WordPress Plugin Radically Improves User Experience
Adobe released a PDF Embed WordPress plugin provides additional ways to display PDFs online in a way that makes them user friendly, pleasantly interactive and useful. The new plugin makes PDF more usable on the web, with four different ways to view a file without any of the inconveniences....