HPV vaccine: defense against the anus cancer
HPV viruses are responsible for more than 80% of anal cancers, a rather rare disease. Studies (Cancer 2010) have shown that a change in sexual habits has caused an increase in these cases in some countries. Researchers have therefore sought to determine what proportion of the HPV vaccine, used primarily for the protection of the uterus cervical cancer, is effective in preventing anal cancer.
Since early 2007, there is a vaccine against specific types of HPV. This vaccine defends against the most widespread HPV types (HPV 16, 6, 11, and 18), that can be a reason of disease especially in the genital and anal areas.
Infections with these human papillomavirus (HPV) are, among others, the cause of genital warts, the cervix cancer and in addition as those of the anus.
4210 women at the age of 18 and 25 years had part in this research. The women were a part of the study group of Costa Rica for the vaccination of more than 6000 women. Participants received a vaccine against HPV. The vaccination was repeated 1 and 6 months later. After four years, a sample of participants from the anus was removed and an HPV infection sought. The researchers also determined the effectiveness of the defense against the cervix cancer.
In the whole group, that is to say women who have had contact with the virus before HPV vaccine plus those who have never previously been in contact with this virus, the HPV vaccine was used to prevent 62% of cases of anal HPV infection and 76% infection of the lining of the cervix. Among women who had not been in touch with this virus, the protection was even more striking: up respectively 83.6% and 87.9% of infections have been avoided.
According to the authors, the HPV vaccination appears to offer better protection against viral infection by anal HPV 16 and HPV 18. Women who had not been in touch with the HPV vaccine before were even better protected.
Current recommendations for vaccination in Switzerland
Young women should always be vaccinated against HPV, if possible before first sex.
The Federal Office of Health therefore recommends that the basic immunization of all girls and young women 11 to 19 years. For women between 20 and 26 years, the doctor and patient must decide together whether the vaccine is supposed to or not.