A new study released in this week’s British Medical Journal finds that the human papillomavirus, or HPV, vaccine, Gardasil, given to young women to help prevent cervical cancer may have some additional benefits for women who are already infected with HPV.
Gardasil maker Merck funded the study and found that the vaccine reduced re-occurrence of HPV related diseases by 46% among women who were infected prior to vaccination.
According to the Center for Disease Control, HPV is the most common sexually transmitted infection. By the CDC’s count, 90% of HPV cases are naturally cleared by the body, in two years. But, when not cleared, those infections can lead to genital warts and cervical cancer.
According to Dr. Elmar Joura, lead author of the study, “many people think that the vaccine only works in young girls prior to their sexual debut.” Joura is an associate professor at the Medical University of Vienna, Comprehensive Cancer Center. He went on to say, “We could prove with our study that also women with disease get a substantial benefit by the vaccine.”
The study looked at 1,350 women from 24 different countries. The women were between the ages of 15 and 26 and were provided either the vaccine or a placebo. While women with a previous history of HPV related disease were excluded from the study, women enrolled in the trial were not screened for HPV related disease. As a result, women with ongoing infection and disease were vaccinated.
When looking specifically at vaccinated enrollees who underwent cervical surgery, their risk of developing of any additional disease after surgery was 6.6 cases for every 100 women. When looking at women who had surgery and were given the placebo, their risk of developing disease nearly doubled to 12.2 cases for every 100 women.
While the numbers seem promising, Jane Kim with the Harvard Medical School of Public Health was wary of expanding the results of the study to the general public. In an accompanying editorial in BMJ she wrote, “contrary to the author’s suggestion, generalizations to women who are considering HPV vaccination after treatment for related disease require a better understanding of individual characteristics and heterogeneities in these different populations.”
Dr. Elizabeth Poyner, a gynological oncologist with Lenox Hill Hospital in New York said the study furthers our knowledge about the vaccine, but was cautious about implementing it in practice. “This is not a practice change. It helps to further define the impact of HPV vaccine. But this shouldn’t change who we are giving the vaccine to,” said Poyner.