Why in the News?
- Recent evidence from a large Swedish study has shown that high coverage of HPV vaccination through school-based programmes reduces precancerous cervical lesions even among unvaccinated women, confirming a herd protection effect.
- The findings are relevant for India, which is planning a nationwide school-based HPV vaccination programme to reduce its high cervical cancer burden.
About Human Papillomavirus (HPV)
- Nature of Virus: Human Papillomavirus (HPV) is a small, double-stranded DNA virus belonging to the papillomavirus family and comprises more than 200 related virus types.
- Transmission: Over 40 HPV types spread through direct sexual contact and intimate skin-to-skin contact, making HPV the most common sexually transmitted infection globally.
- Infection Pattern: Most HPV infections are asymptomatic and are cleared naturally by the immune system; however, persistent infection with certain strains can lead to cancer.
- Oncogenic Strains:At least 14 HPV types are classified as high-risk, with HPV-16 and HPV-18 being the most oncogenic, responsible for about 70% of cervical cancer cases worldwide.
- HPV types 16 and 18 are linked to most cervical cancers, while types 6 and 11 cause genital warts.
- Cancer Burden: More than 95% of cervical cancer cases are linked to persistent HPV infection, and HPV overall contributes to around 5% of all cancers globally.
- Diseases Caused: HPV can cause genital warts and cancers of the cervix, vulva, vagina, penis, anus, and oropharynx, affecting both men and women.
- Disease Burden: Cervical cancer develops in the cervix (lower part of the uterus) and is the second most common cancer among Indian women.
- Treatment: There is no specific treatment for HPV infection itself; most infections resolve spontaneously without intervention.
- Prevention: HPV vaccines are preventive, not curative, and work by stimulating antibody production that blocks viral entry, thereby preventing HPV-related cancers and genital warts.
HPV Vaccination
- Nature of Vaccine: The HPV vaccine is administered as a series of doses designed to protect against Human Papillomavirus infection, which can otherwise progress to cervical cancer and genital warts.
- Preventive Role: The vaccine prevents new HPV infections and thereby reduces the risk of HPV-associated cancers; it does not treat existing HPV infection.
- Age Efficacy Window: HPV vaccination is most effective when given between 9–26 years of age, ideally before exposure to the virus through sexual contact.
- Effect after Infection: Once a person is already infected with HPV, the protective efficacy of the vaccine declines, though it may still prevent infection from other HPV types.
- Pregnancy Consideration: The HPV vaccine is not administered during pregnancy as a precautionary measure.
- HPV Vaccination in India: Government Initiative: The Government of India plans to vaccinate girls aged 9–14 years to significantly reduce the burden of cervical cancer.
With reference to Human Papillomavirus (HPV), consider the following statements:
1. Human Papillomavirus (HPV) is a double-stranded DNA virus, and persistent infection with certain strains can lead to cancers of the cervix and other organs.
2. HPV vaccines are curative in nature and can eliminate existing HPV infections.
3. HPV vaccination is most effective when administered before exposure to the virus.
Which of the statements given above are correct?
(a) 1 and 2 only
(b) 1 and 3 only
(c) 2 and 3 only
(d) 1, 2, and 3
Answer: (b) 1 and 3 only
Explanation:
Statement 1 – Correct: Human Papillomavirus is a small, double-stranded DNA virus. Persistent infection with high-risk HPV strains can cause cancers of the cervix, vulva, vagina, penis, anus, and oropharynx.
Statement 2 – Incorrect: HPV vaccines are preventive, not curative. They do not eliminate existing HPV infections or treat HPV-related cancers; they only prevent new infections.
Statement 3 – Correct: HPV vaccination is most effective when given before exposure to the virus, ideally in the 9–26 years age group, prior to the onset of sexual activity.
