When investors debate the merits and risks of pharmaceutical company Merck (MRK 0.10%), the focus tends to be on the patent expiration of its asthma drug Singulair and the massive sales growth of its diabetes drugs Januvia and Janument. While both are important issues, the company has a diverse range of products on the market and 11 blockbuster drugs. One of those is Gardasil, a vaccine that prevents HPV infections. In 2012, the vaccine brought in $1.6 billion in sales, and its year-over-year growth has helped to partially offset the revenue decline caused by Singulair's patent expiration. However, can sales of Gardasil continue to grow? Or will GlaxoSmithKline's (GSK -0.92%) competing vaccine Cervarix be able to eclipse Merck's drug in the years to come?

Health care analyst Max Macaluso discusses the competition between these two vaccines in the following video.