From the smallest biotech to the biggest pharmaceutical stock, The Motley Fool's Market Check-Up covers the health-care sector's biggest headlines, hottest market movers, and Obamacare's ongoing rollout.

In this segment, health-care analyst David Williamson discusses Merck's (NYSE:MRK) latest anti-viral successes. The company now has a new HPV vaccine that offers protection not only against the four strains that the company's previous vaccine covers against, but also against five additional strains. David also says he likes Merck's hepatitis C drug combo, currently in phase 2 trials, even though it may be a bit late to the game in this space. David tells investors what he likes about these two developments but also discusses why he isn't excited about these drugs just yet.