FDA approved on Friday the use of Gardasil vaccine in fighting vaginal and vulvar cancers, in addition to cervical cancer, after an extended study initiated by Merck, the pharmaceutical company that manufactures the vaccine. More than 15,000 women were tested and none of the ones who received the shot developed HPV-related precancers in the vagina or vulva, compared to 10 of the women who received a placebo vaccine.

Gardasil was first approved in 2006 and it is used for prevention of cervical cancer in girls and women ages 9 to 26. The vaccine works by protecting against strains of the human papilloma virus, or HPV, which is transmitted by sexual contact and causes genital warts, the cause for about 70 percent of cervical cancers. HPV is the most common sexually transmitted disease in the USA, with 6.2 million Americans infected each year, according to the Centers for Disease Control and Prevention.

As cancer treatment is still a delicate issue and there is no drug to have proven 100% effective, the Gardasil vaccine generated a lot of controversy ever since it hit the market. Merk’s proposal of extending the market to women ages 27 to 45 was rejected by the Food and Drug Administration, as a recent government-funded study released last month concluded that the vaccine is not effective for women in their 20s and older.

The use of the vaccine has similar effects with other injections such as fainting and injection pain as well as headache, nausea and fever, the FDA said, but the label was updated to include additional reports of blood clots, autoimmune diseases and death in some patients who were given the vaccine.