HPV Vaccination And Cervical Cancer Prevention

Cervical Cancer is responsible for more than any gynecologic-related deaths world wide than any other malady, making it the most important preventable disease in women’s health today. Worldwide each year 4, 93,243 women are diagnosed of cervical cancer of whom 2,40,000 women die of this disease (WHO). India contributes more than ¼ of the global burden. Each year about 1,32,082 cases of this cancer are diagnosed and more than 74,118 women die of this disease, this cancer being most common cancer of women in our country.

Human Papilloma Virus (HPV) infection is now a well established cause of cervical cancer. Human papilloma virus is a double stranded DNA virus of papovaviride family. More than 100 types described; 30 infect ano genital tract. High risk types of 16, 18, 31, 33, 35, 45, 51, 52, 56, 58, 59 and 68 are associated with neoplasia. HPV 16 and 18 in 70% of this cancer cases world wide and 45 and 31 with a further 10% of this cancer case. Low risk types 6, 11, 42, 43, 44 associated with genital warts (cardyloma) and do not cause cancer. Almost 100% cancer cases of cervix are associated with HPV, 90% cases of anal cancer, 40% cases each of vulva, vagina, penis and about 12% cases of oral cavity and pharynx are HPV related cancers.

Cervical Cancer ranks the first most frequent cancer among the women between 15-44 years. According to WHO/ICO information centre on HPV and cervical cancer, India has the population of 365.71 million women ages 15 years and older who are at risk of developing cancer. About 6.6% of women in general population are estimated to harbor cervical infection at a given time and 76.7% of invasive cervical cancer in India are attributed to HPVs 16 & 18. Human papilloma virus spread primarily through sexual intercourse. Infection can occur in as little as one month after the fist sexual contact.

Though HPV is a necessary cause of cervical cancer but is not a sufficient cause. Other Cofactors are necessary for progression from cervical HPV infection to cancer. High parity, tobacco smoking, longterm use of oral contraceptives and coinfection with HIV have been identified as established co-factors; co-infection with chlamydia trachomatis and herpes simplex virus type -2, immunosuppression and certain dietary deficiencies are other probable co-factor.

With the knowledge of HPV (Oncogenic types) as the causative agent of this cancer, two types of vaccination strategies have been aimed at prophylactic vaccine is Virus Like Particle (VLP)