Lucan · Conditions

HPV vaccination

Australian guidance: RANZCOG C-Gyn 18 HPV Vaccine Guidelines (2024) + AU Immunisation Handbook

1. Definition and epidemiology

Human papillomavirus (HPV) is a small, non-enveloped double-stranded DNA virus with over 100 genotypes identified; approximately 40 types specifically infect the anogenital tract. Up to 90% of the general population will acquire at least one genital HPV type during their lifetime, with initial infection typically occurring close to sexual debut. In Australia, the 2018 age-standardised cervical cancer incidence was 7.3 per 100,000 women, with Aboriginal and Torres Strait Islander women experiencing more than double the incidence of non-Indigenous women at 20.3 per 100,000; Australia has committed to cervical cancer elimination by 2035. Prior to the national vaccination program, about two-thirds of Australian women aged 15 to 20 years had HPV DNA detected at cervical screening.

2. Pathophysiology

HPV requires a microabrasion or breach in the epithelial surface to access and infect basal epithelial cells within the squamocolumnar junction of the cervix. Once inside, the viral genome integrates into host DNA or persists episomally. High-risk oncogenic types, principally HPV-16 and HPV-18, encode two key oncoproteins: E6 and E7. E6 targets the p53 tumour suppressor protein for proteasomal degradation, abolishing apoptosis and allowing accumulation of DNA mutations. E7 binds and inactivates the retinoblastoma protein (Rb), releasing the E2F transcription factor and driving uncontrolled cell cycle progression. Infectious virions are only produced in terminally differentiated epithelial cells, meaning the basal compartment sustains latent infection while surface cells shed virus. HPV types 16, 18, 31, 33, 45, 52 and 58 carry high oncogenic risk; HPV-16 is the single most common cause of HPV-related cancers worldwide. Low-risk types 6 and 11 do not integrate and instead produce benign proliferative lesions such as genital warts and recurrent respiratory papillomatosis. In about 3 to 10% of infections the virus persists beyond 12 to 24 months; persistent infection with a high-risk type is the necessary precursor to malignant transformation, which typically occurs 10 to 20 years after infection.

3. Clinical presentation and diagnostic criteria

HPV infection is most often subclinical. When symptomatic, the clinical picture depends on the infecting genotype. Low-risk types (6, 11) cause condylomata acuminata (anogenital warts): soft, flesh-coloured, exophytic papules or plaques on the vulva, vagina, cervix, perianal region or penis that may be asymptomatic, pruritic, tender or occasionally bleed. Recurrent respiratory papillomatosis, caused exclusively by types 6 and 11, presents as hoarseness and progressive airway obstruction in both juvenile and adult forms. High-risk types cause a spectrum from low-grade squamous intraepithelial lesion through high-grade cervical intraepithelial neoplasia (CIN 2/3) to invasive squamous cell or adenocarcinoma. Early cervical cancer is typically asymptomatic, detected on screening; later disease presents with intermenstrual or postcoital bleeding, offensive vaginal discharge, and in advanced cases pelvic pain or ureteric obstruction. HPV-associated cancers also arise at the vulva, vagina, anus, penis and oropharynx. There are no formal diagnostic criteria for HPV vaccination candidacy; eligibility is age and immunocompromise driven.

4. Investigations and AU-specific cutoffs

There is no routine blood test to confirm HPV immunity or infection status before vaccination; vaccination is recommended regardless of prior HPV exposure in eligible groups. The primary investigation underpinning this program is the National Cervical Screening Program (NCSP): all vaccinated women are still recommended to undergo five-yearly cervical HPV screening commencing at age 25, as vaccine-type HPV prevalence in 2017 to 2018 was only 2.1% but other oncogenic types remain in circulation. Colposcopy and cervical biopsy are indicated when HPV screening detects high-risk genotypes, particularly with concurrent abnormal cytology. For anogenital warts, diagnosis is clinical; biopsy is reserved for atypical or treatment-resistant lesions. In immunocompromised men who have sex with men (MSM), high-resolution anoscopy may be considered for anal intraepithelial neoplasia surveillance given the more than 30-fold higher anal cancer incidence in this group compared with other men.

5. Management

The cornerstone of management is prophylactic vaccination with Gardasil 9 (9vHPV, see Section 6), delivered within the National Immunisation Program (NIP) schedule. RANZCOG C-Gyn 18 signposts clinicians to the Australian Immunisation Handbook as the definitive reference and confirms the vaccine began in Australia in 2007, is funded free of charge for individuals aged 12 to 25 under the NIP, and is safe and highly effective against nine HPV strains. For immunocompetent individuals who start vaccination at age 9 to 25 years, a single dose is recommended; the optimal age is 12 to 13 years via the school-based Year 7 program. For those who begin at 26 years or older, three doses are required at 0, 2 and 6 months. All immunocompromised patients regardless of age require the three-dose schedule. MSM of any age who are unvaccinated should receive HPV vaccine, with dose number determined by age at commencement. HPV vaccine is not recommended during pregnancy due to limited safety data; any doses remaining at conception should be deferred until postpartum. Breastfeeding is not a contraindication. Genital warts are managed with topical agents (podophyllotoxin, imiquimod) or procedural ablation; vaccination does not treat existing infection. Vaccinated women must continue cervical screening, as HPV types outside the nine covered types still cause cervical malignancy.

6. Pharmacology and AU PBS notes

The only HPV vaccine available in Australia is Gardasil 9 (9vHPV), sponsored by Merck Sharp and Dohme (Australia). It is a recombinant virus-like particle (VLP) vaccine containing the L1 major capsid protein of nine HPV types: 6, 11, 16, 18, 31, 33, 45, 52 and 58. VLPs are non-infectious and cannot replicate. Each 0.5 mL intramuscular dose contains aluminium hydroxyphosphate sulfate adjuvant (500 micrograms aluminium). The vaccine is registered for males and females aged 9 to under 46 years; ATAGI extends recommendation to MSM and immunocompromised individuals of any age. Gardasil 9 is funded under the NIP for individuals aged 12 to 25 years; outside this range it is available on private prescription. There is no PBS streamlined authority code; it is listed on the NIP schedule, not PBS. The vaccine must be stored at plus 2 to plus 8 degrees Celsius and must not be frozen or exposed to light. Efficacy against vaccine-type cervical, vulval and vaginal neoplasia caused by HPV-31, 33, 45, 52 and 58 is 97.4% (95% CI 85.0 to 99.9%), with non-inferiority demonstrated against HPV-16 and HPV-18. Single-dose efficacy against persistent infection was 97.5% in women aged 15 to 20 years in clinical trial data. Gardasil 9 can be co-administered with dTpa, dTpa-IPV, hepatitis B, MenACWY and COVID-19 vaccines using separate syringes and sites.

7. Complications and monitoring

Vaccine adverse events: Injection site reactions (pain, erythema, swelling) occur in 80 to 90% of recipients and are the most commonly reported adverse event; they are less frequent in younger adolescents. Systemic reactions including headache, fever, nausea, dizziness and fatigue occur at rates comparable to control vaccine recipients. Syncope is identified through post-marketing surveillance as a common immediate post-vaccination reaction in adolescents (currently 7.1 per 100,000 doses in Australia), attributable to the vaccination process rather than vaccine components; sitting or lying down for 15 minutes after injection is recommended. Anaphylaxis risk is 0.32 per 100,000 doses, consistent with other vaccines. The absolute contraindications are prior anaphylaxis to any HPV vaccine component or to yeast. There is no consistent evidence linking 9vHPV to new-onset autoimmune disease, primary ovarian insufficiency, complex regional pain syndrome or postural orthostatic tachycardia; the WHO Global Advisory Committee on Vaccine Safety, the European Medicines Agency and the Australian TGA have all confirmed this. Guillain-Barre syndrome association has not been confirmed in any large well-conducted study following an initial signal in a single French cohort.

Post-vaccination surveillance: Women who have received HPV vaccine must continue participation in the NCSP with five-yearly HPV-based cervical screening from age 25. The first screening visit is also a check-up opportunity for vaccination catch-up in those not vaccinated in school. Surveillance of genital warts and CIN rates via sentinel surveillance programs documents program impact. Aboriginal and Torres Strait Islander women require targeted outreach for both vaccination and screening given persistent incidence inequity. Australia tracks toward cervical cancer elimination (target less than 4 new cases per 100,000 annually) by approximately 2028 if current vaccination and screening coverage is maintained.

Written for Australian practice and grounded in the guidance named above. Study material only — not medical advice. Always check against current guidelines.