HPV vaccination and screening

HPV vaccination and screening

HPV vaccination and screening

On this page

HPV & Oncogenesis - Viral Villains

  • High-Risk HPV (HR-HPV): Types 16, 18, 31, 33.

    • Viral DNA integrates into the host genome.
    • ↑ E6 oncoprotein → degrades p53 (tumor suppressor).
    • ↑ E7 oncoprotein → inhibits Rb (retinoblastoma protein).
    • Result: Unregulated cell cycle → potential for malignancy.
  • Low-Risk HPV (LR-HPV): Types 6, 11.

    • Cause condylomata acuminata (anogenital warts).
    • Viral DNA usually remains episomal (non-integrated).
  • Associated Cancers: Cervical, anal, penile, vaginal, vulvar, and oropharyngeal.

⭐ HPV types 16 and 18 account for over 70% of cervical cancers and a significant portion of other HPV-associated cancers.

HPV Vaccination - Gardasil's Guard

  • Gardasil 9 (9-valent): Recombinant vaccine against HPV L1 major capsid protein, forming virus-like particles (VLPs).
  • Targets: HPV types 6, 11 (condyloma acuminata) & 16, 18, 31, 33, 45, 52, 58 (cervical, anogenital, oropharyngeal cancers).
  • Administration Schedule:
  • Age 9-14: 2 doses at 0 and 6-12 months.
  • Age ≥15 or Immunocompromised: 3 doses at 0, 1-2, and 6 months.
  • Catch-up recommended up to age 26; shared decision-making for ages 27-45.

⭐ Vaccination does not eliminate the need for routine cervical cancer screening (e.g., Pap test) as it doesn't cover all oncogenic HPV types.

HPV infection and antibody neutralization mechanism

Cervical Cancer Screening - The Pap & HPV Hunt

  • Goal: Detect precancerous lesions (Cervical Intraepithelial Neoplasia, CIN) caused by high-risk HPV (hrHPV) before they progress to invasive carcinoma.
  • Dual Methods:
    • Pap Smear (Cytology): Detects cellular atypia; looks for koilocytes.
    • hrHPV Test (Virology): Detects DNA from high-risk HPV strains (e.g., 16, 18, 31, 33).

Koilocytes on Pap smear showing perinuclear halo

⭐ HPV types 16 and 18 are responsible for approximately 70% of cervical cancers. Most HPV infections are transient and clear spontaneously within 1-2 years.

High‑Yield Points - ⚡ Biggest Takeaways

  • High-risk HPV (16, 18) cause most cervical cancers; low-risk HPV (6, 11) cause genital warts (condylomata acuminata).
  • The 9-valent HPV vaccine is prophylactic and recommended before sexual debut; it does not treat active infections.
  • Primary screening combines Pap tests (for koilocytes) and HPV DNA testing.
  • Koilocytes are pathognomonic, showing a perinuclear halo and a wrinkled, "raisinoid" nucleus.
  • Cervical cancer screening starts at age 21, regardless of vaccination or sexual history.

Practice Questions: HPV vaccination and screening

Test your understanding with these related questions

A 38-year-old woman makes an appointment with her family physician for a routine check-up after being away due to travel for 1 year. She recently had a screening Pap smear, which was negative for malignancy. Her past medical history is significant for a Pap smear 2 years ago that reported a low-grade squamous intraepithelial lesion (LSIL). A subsequent colposcopy diagnosed high-grade cervical intraepithelial neoplasia (CIN2). The patient is surprised by the differences in her diagnostic tests. You explain to her the basis for the difference and reassure her. With this in mind, which of the following HPV serotypes is most likely to be present in the patient?

1 of 5

Flashcards: HPV vaccination and screening

1/10

What is the cancer risk associated with HPV31?_____

TAP TO REVEAL ANSWER

What is the cancer risk associated with HPV31?_____

High

browseSpaceflip

Enjoying this lesson?

Get full access to all lessons, practice questions, and more.

Start Your Free Trial