Women protecting against HPV infection and cervical cancers by vaccinating with human papillomavirus quadrivalent vaccine (Gardasil) are less likely to have abnormal Pap test results.

Dr. Warner K. Huh, MD of the University of Alabama Birmingham made an analysis of more than 18,000 women who participated in clinical trials testing the drug in the United States, Europe and Asia.

The results showed that women who had been immunized were 43 percent less likely to have one type of problematic results three years after they were given the shot. The findings also show about a 16 percent to 35 percent drop in the various types of less serious abnormalities, which often require additional testing.

Dr. Huh underlined that the results do not prove the vaccine prevents cervical cancers, but show that vaccination prevents cellular changes that often trigger procedures and surgery.

“This is important because a lot of physicians across the U.S. may never see a case of cervical cancer in their lifetimes. However, almost every clinician involved in women's health care -- and every woman -- is familiar with the importance of an abnormal Pap smear,” Dr. Huh said in an interview, according to MedPage Today.

Gardasil, made by Merck & Co., protects against four strains of human papillomavirus that account for 70 percent of cervical cancers and 90 percent of genital warts. It's approved for use in females ages 9 to 26, and the Centers for Disease Control & Prevention recommends girls ages 11 and 12 get the vaccine.

The findings were presented at the annual meeting of the Society of Gynecological Oncologists.