Future growth? Merck & Co., Inc. (NYSE:MRK) would see the most gains from an influx of vaccination patients. Gardasil is approved for two more HPV types than Cervarix. And Gardasil received Food and Drug Administration approval for vaccinating men against HPV to help protect against various types of cancer including anal and penile. Gardasil's sales grew 35% last year to $1.6 billion while Cervarix sales fell 46% to around $412 million. Cervarix will continue to fall without broader indications — especially now that the U.K.'s National Health Service has switched its official recommendation from Cervarix to Gardasil. And both drugs could suffer if Japan's current investigation into the safety issues of the vaccines turns out to be anything other than caution. So Merck & Co., Inc. (NYSE:MRK)'s winning the vaccine race. But how dependent are the companies on having a successful product in this space?