Ryuugan: Dragon Eye (2005)

Blurb:
Ten years ago, a terrible virus swept the globe. It turned its victims into bloodthirsty monsters called Dracules, and the only cure is death. Now, with humankind on the brink of extinction, only the elite warriors of the Vius Squad stand between chaos and civilization. New recruit Leila Mikami is one of the squad’s most promising young warriors, but she has another agenda: Her parents were killed by a Dracule, and she’s determined to take revenge. To do this, she has to find the Dragon Eye–a magic weapon that will make her the most powerful warrior in the world.

Source: www.anisearch.com/manga/3211