HPV vaccination Flashcards
What cancers can HPV cause?
Cervical Vulva Vagina Penis Some head and neck
Which strains cause most cervical cancers?
16 and 18 (70-80%)
Which strains cause genital warts?
6 and 11
Benefits of HPV vaccination:
- Reduces infection of vaccine related HPV types
- Reduces the incidence of precursor lesions and potentially malignant lesions
Who is vaccinated in Australia/NZ?
- Boys and girls
- High school age in Australia
- 9-27 in NZ
How do the HPV vaccines work?
- Contain virus like proteins (not live or attenuated)
- IM injection *–
- Induce antibody response
- Not therapeutic
Which vaccine is used in Australia and New Zealand?
- Gardasil 9
Which strains do Gardasil protect against?
- 6, 11, 16, 18, (13, 33, 45, 52, 58)
- Prevents 90% of cervical cancers
Dosage of Gardasil
- 2 doses 5-13 months apart
- If immunocompromised or older than 15 need 3 doses
Adverse reactions:
- Serious: Anaphylaxis (around 1-3 per million)
- Mild: Headache, fever, dizziness, muscle pain, local reaction
- Not recommended for use in pregnancy
Which strains do cervarix protect against?
16 and 18
Describe the viral composition of Gardasil HPV vaccine. (2 marks)
• No live, attenuated or killed virus present
• Virus-like proteins designed to mimic the HPV L1 capsid protein
o Antibodies then develop to the capsid protein
• Contains virus like proteins of HPV 6, 11, 16 & 18
b. Discuss four (4) benefits and three (3) limitations of Gardasil HPV vaccination in preventing genital tract dysplasia. (7 marks)
Benefits
• Prevention from contracting HPV 16 and 18, which causes 80% of cervical cancers
• Prevention from VAIN/VIN from 16 &18 and their associated cancers
• Some cross-immunity against other strains may be present
• Highly effective when given in young women (ideally before the age of sexual debut)
• Reduces HPV risk in the male partner
• Excellent safety profile
Limitations
• Does not cover all strains of HPV implicated in VIN/VAIN
• Not protective against strains of HPV that a woman has already been exposed to
• Reduced effectiveness in immunosuppressed women
• No evidence that effective in women over the age of 45 and immunogenic response declines with age
• Does not abolish the need for cervical screening
• Long term effects and duration of immunity unknown
c. Discuss one (1) benefit and one (1) limitation of Gardasil HPV vaccination in preventing genital warts. (2 marks)
Benefit
• Highly effective in preventing development of genital warts from HPV 6 and 11- 90%
Limitation
• Effectiveness may be reduced in immnosuppressed women
• Does not cover the other HPV types that cause 10% of genital warts
A 23 year old nulliparous woman who did not have HPV vaccination at school was vaccinated by her GP. A month after her first dose she discovers she is 9 weeks pregnant. She is seeing you because she wants to continue the pregnancy and is concerned about the effect of having inadvertently commenced the HVP vaccination program while pregnant.
d. Outline two (2) pieces of advice you will give to the patient and justify each with respect to HPV related issues. (4 marks)
There is no evidence that the HPV vaccine causes harm to pregnancy
o It does not contain any live, dead or attenuated virus so there is no risk of viral transmission
o Studies have not been done with administration to pregnant women, but there is no evidence of harm of women who have become pregnant whilst receiving vacciness
• We would avoid giving the next vaccine (scheduled for 2 months after the first) until after the end of the pregnancy and then start once the baby is born
o Gardasil vaccine is safe in lactation
o There is no evidence for decreased efficacy of the vaccine where pregnancy interrupts the vaccine schedule
