When Merck Pharmaceuticals received approval from the FDA for the Gardasil vaccine in 2006, it was for the protection against four strains of HPV and is therefore referred to as quadrivalent.
Those strains of HPV included two high risk strains 16 and 18 known to cause precancerous and cancerous lesions and two low risk strains 6 and 11 which cause genital warts.
However, as much as people are unaware that HPV causes any cancer aside from cervical, most are also unaware than since 2006 Merck has received approval from the FDA and Gardasil protecting against much more than cervical cancer.
Shortly after being approved to protect against cervical cancer, also in 2006, it was also approved for the protection of cancerous lesions involving the vagina and vulva. While this information was clearly incorporated into the updated product fact sheet, very little has been done beyond that to educate the public regarding this increased protection.
In 2010, the FDA added yet another group to the list, precancerous and cancerous anal lesions resulting from HPV, Gardasil was shown to provide protection against these cancers as well, and the list of cancers continues to grow as well as the vaccine’s ability to provide protection against them.
Cervarix, a second HPV vaccine manufactured by Glaxo-Smith Kline does not protect against the low risk strains of HPV which cause genital warts. It does protect against high risk strains 16 and 18 and is believed to confer some immunity to three other high risk strains as well.
Because of the rapid rise in oropharyngeal cancers which are expected to exceed the rate of cervical cancers by the year 2020 according to Maura Gillison, MD and oncologist at The University of Ohio who has conducted much of this research, this has now resulted in a widespread call for extensive testing of these vaccines used against the infection.
It would make sense that studies that have already shown these vaccines to provide protection against other forms of HPV related cancer from these same strains in other parts of the body would also provide protection against HPV induced oropharyngeal cancers.