The Royal Women’s Hospital, in collaboration with the Victorian Cytology Service, found out that seven strains of human papillomavirus (HPV) is responsible for 93% of cervical cancer in Australian women. Out of that 93%, 77% is linked with HPV 16 and 18 while 16% is by HPV 31, 33, 45, 52 and 58. The hospital hopes that Australia’s National HPV Vaccination Program will adopt the new HPV vaccine Gardasil 9, which can provide protection against all seven strains, as early as 2018. The study was published in International Journal of Cancer.
Cervical cancer is characterized by abnormal cells growing in the cervix’s lining of a woman. The World Health Organization (WHO) reported 270,000 deaths worldwide from this disease in 2012. In Australia, there were 223 deaths in 2014. Though the condition is the most common HPV-linked disease, the virus also causes cancer of the vagina and vulva in women, penis in men, and anus and neck in both men and women.
Aside from cancers, HPV is also the culprit behind genital warts, thus the virus’ name (after “papillomas” or warts). The virus is transmitted sexually; penetrative sex is not required and skin-to-skin contact is enough. More than 150 strains are known and each one is identified with a number. HPV 16 and 18 strains are the leading causes of cervical and other HPV-related cancers. HPV 6 and 11 are not carcinogenic but they are the ones that cause genital warts. Luckily, vaccines provide protection but they cannot treat the diseases if already present. The best time, therefore, to get vaccinated is before a person gets sexually active.
Currently, there are three types of HPV vaccines: the bivalent Cervarix (from GlaxoSmithKline) which protects against HPV 16 and 18; the quadrivalent Gardasil (from Merck) for HPV 6, 11, 16 and 18; and the new Gardasil 9 (also from Merck), a nonavalent vaccine against HPV strains 6, 11, 16, 18, 31, 33, 45, 52 and 58.
All three vaccine types are effective against HPV 16 and 18, which already account for the majority of cervical cancer cases. The quadrivalent and nonavalent variants have additional protection against genital warts. The nonavalent vaccine alone has protection against other cancer-causing strains, which makes it the most powerful among HPV vaccines.
In 2007, Australia was the first country to institute a government-funded program for HPV prevention which provides free quadrivalent vaccines for boys and girls aged 12 to 13. While current Gardasil is proven effective already, Gardasil 9 is seen more favorably for future vaccinations due to its wider HPV coverage. It can actually increase cervical cancer prevention from 77% to 93%.
The study’s senior author Professor Suzanne Garland said that “if we continue with this high coverage of vaccination, we could almost wipe out cervical cancer in women.”
Gardasil 9 was approved by the US Food and Drug Administration in late 2014. The vaccine is hoped to become part of Australia’s National HPV Vaccination Program sometime in 2018.