Author(s): Rashidul Alam Mahumud 1,2,3,4,5,*, Khorshed Alam 1,2, Syed Afroz Keramat 1,2,6, Gail M. Ormsby 7, Jeff Dunn 1,8,9, Jeff Gow 1,2,10
Cervical cancer (CC ) is the third most common cancer and the leading cause of cancer-related deaths in women worldwide . Approximately 570,000 new cases of CC were diagnosed in 2018, composing 6.6% of all cancers in women . The burden of CC is an alarming issue across the globe, especially in low-and middle-income countries (LMICs ). Approximately 85% of CC cases and 90% of deaths from CC occur in LMICs . Persistent infections with human papillomavirus (HPV ) are a key cause of CC and is an established carcinogen of CC . HPV is predominantly transmitted to women of reproductive age through sexual contact . Most HPV infections are transient and can be cleared up within a short period, usually a few months after their acquisition. However, untreated HPV infections can continue and evolve into cancer in some cases. There are more than 100 types of HPV infections, and high-risk types develop into CC . Thirteen high-risk HPV genotypes are known to be predominantly responsible for malignant and premalignant lesions of the anogenital area , and these are the leading causes of most aggressive CC . Further, HPV is also responsible for the majority of anogenital cervical cancers, including anal cancers (88%), vulvar cancers (43%), invasive vaginal carcinomas (70%), and all penile cancers (50%) globally .
The burden of CC (i.e., high incidence and mortality rates) globally is preventable through the implementation of a primary prevention strategy such as vaccination . There are vaccines that can protect common cancer-causing types of HPV and reduce the risk of CC significantly. Three types of HPV vaccines, namely bivalent (Cervarix), quadrivalent (Gardasil) and 9-valent vaccine (Gardasil-9), are currently available in the market. Unfortunately, as of March 2017, only 71 countries (37% of all countries) have included HPV vaccines in their national immunization programs for girls, and 11 countries (6%) included for both sexes . The first global recommendation on HPV vaccination was proposed by the World Health Organization's Strategic Advisory Group of Experts on Immunization in October 2008 , where HPV vaccination was recommended for girls aged 9-13 years. This recommendation was updated in April 2014 , with the emphasis to include extended 2-dose HPV immunization for girls aged 9-14 years, who were not immune compromised. With the recent licensing of the 9-valent vaccine and the introduction of various HPV vaccination strategies, an update on the current recommendations of HPV vaccination are inevitable. The goals of the immunisation program are to combat the acquisition and spread of HPV infections, and achieving optimum coverage through effective delivery systems. According to the underlying distribution of HPV infection types of CC , the 9vHPV vaccine builds population-level strong immunity against HPV -6, 11, 16, 18, 31, 33, 45, 52, and 58 infections  that cumulatively contributed approximately 89% of all CCs globally . With respect to the primary prevention of HPV infection, it is expected that the 9vHPV vaccine can reduce the lifetime risk of...