What is HPV?
Human papillomavirus (HPV) is a common virus affecting both men and women. HPV is spread through genital contact during sex with someone who has the virus. The virus passes through tiny breaks in the skin and is not spread through blood or other body fluids. Condoms offer limited protection, as they do not cover all of the genital skin. Most sexually active people will have a genital HPV infection at some time in their lives. While the body usually clears the infection naturally and there are no symptoms, it can sometimes cause serious illness, including:
- almost all cases of cervical cancer
- 90% of anal cancers
- 65% of vaginal cancers
- 60% of oropharyngeal cancers (cancers of the back of the throat)
- 50% of vulva cancers
- 35% of penile cancers
- almost all cases of genital wartswarts
Which HPV vaccine has been used?
A vaccine that protects against four types of HPV (4vHPV or Gardasil®) has been given on a three-dose schedule given over at least 6 months under the National Immunisation Program since 2007. This vaccine protects against the two high-risk HPV types (types 16 and 18) which cause 70 per cent of cervical cancers in women and 90 per cent of all HPV-related cancers in men, and against two other low-risk HPV types (types 6 and 11) which cause 90 per cent of genital warts in men and women.
What is changing and why?
From 2018 onwards, the National Immunisation Program will adopt an HPV vaccine that covers nine types of HPV (9vHPV or Gardasil9®). This vaccine protects against more high-risk HPV types that cause over 90% of cervical cancers in women and also protects against additional HPV types that cause cancers in men.
Further, international evidence demonstrates that for any HPV vaccine given to individuals aged under 15 years, two doses given at least 6 months apart is equivalent to the current three-dose schedule. Other comparable countries, such as the United Kingdom, United States, Canada and New Zealand, have already adopted two-dose HPV schedules.
Why is the dosing schedule changing?
The latest international studies1 demonstrate that a two-dose schedule of any HPV vaccine, given to individuals aged 9-14 years of age at least 6 months apart, gives equivalent protection to a three-dose course of vaccine given at 0, 2 and 6 months for most students (exceptions are listed below). Students who have had two doses of HPV vaccine at least 6 months apart are therefore fully vaccinated and do not need a third dose.
Which students still need three doses of HPV vaccine?
A small number of students are still recommended to have three doses of HPV vaccine (at 0, 2 and 6 months) to be protected:
- those who received the first dose of any HPV vaccine when they were 15 years of age or older
- those with significant immunocompromise, regardless of age of commencing HPV vaccination, defined as those with primary or secondary immune-deficiencies (B lymphocyte antibody and T lymphocyte complete or partial deficiencies); HIV infection; malignancy; organ transplantation; or significant immunosuppressive therapy (excluding asplenia or hyposplenia).
What about adolescents who first received 4vHPV vaccine in 2017?
n NSW the second dose of 4vHPV vaccine was deferred in 2017 to accommodate the emergency roll-out of the Meningococcal W Response Program to Year 11 and 12 students in response to a rapid increase in meningococcal W. This means that most Year 7 students will have received two doses of HPV vaccine in 2017 at least 6 months apart and are therefore considered to be fully vaccinated. Year 7 students needing an additional dose (i.e. where a second dose was not given due to student illness or absence) will be offered a second dose in 2018 at routine school clinics. The public health unit will write directly to parents in these circumstances to advise them of these arrangements.
Can an HPV schedule started with 4vHPV vaccine be completed with 9vHPV vaccine?
Yes. It is safe and effective to use 9vHPV in order to complete a vaccination schedule which was commenced with 4vHPV. Individuals who started with 4vHPV and completed with 9vHPV will be adequately protected against 4vHPV types.
If my child has already completed a course of 4vHPV, should they now have 9vHPV vaccine?
Giving additional doses of 9vHPV to those who have completed a course of 4vHPV would provide protection against the extra HPV types (31, 33, 45, 52 and 58) but those doses of 9vHPV are not funded under the National Immunisation Program and must be purchased privately.
What does this mean for my child/patient?
Most Year 7 students will have received two doses of 4vHPV vaccine in 2017 at least 6 months apart and are therefore considered to be fully vaccinated. Year 7 students needing an additional dose (i.e. where a second dose was not given due to student illness or absence) will be offered a second dose in 2018 at routine school clinics. The public health unit will write directly to parents in these circumstances to advise them of these arrangements.
The table below has been developed to assist parents and GPs to understand what these changes mean in various scenarios to ensure that adolescents are fully vaccinated whatever their age or immunocompromise status.
Recommendations regarding doses of 9vHPV vaccine required for those who have already received one or more doses of another HPV vaccine (4vHPV or 2vHPV) at age 14 years or younger
Recommendations for HPV vaccination for adolescents with significant immunocompromise
Adolescents with significant immunocompromise* are recommended to have three doses of HPV vaccine given over at least 6 months. The second dose should be given at least 4 weeks after dose 1, and the third dose should be given at least 12 weeks after dose 2 or 6 months after dose 1 (whichever is later).
* Significant immunocompromise (regardless of age of commencing HPV vaccination) is defined as those with primary or secondary immune-deficiencies (B lymphocyte antibody and T lymphocyte complete or partial deficiencies); HIV infection; malignancy; organ transplantation; or significant immunosuppressive therapy (excluding asplenia or hyposplenia). For immunocompromised individuals, regardless of age of commencing the HPV vaccination, a 3-dose schedule (given over at least 6 months) is required for adequate protection against vaccine-type HPV.
Recommendations for HPV vaccination for adolescents aged 15 years and older at the time of receiving the first HPV vaccine dose
Adolescents who received the first dose of any HPV vaccine when they were 15 years or older are recommended to have three doses of HPV vaccine at 0, 2 and 6 months. Advice about additional 9vHPV doses for these adolescents who have already received one or more doses of HPV is available in the table above.
Why are students vaccinated in Year 7 to prevent this sexually transmitted infection?
National and international recommendations are that the optimal way to prevent HPV infection is to vaccinate young adolescents against HPV before they become sexually active. Further, studies show that the body’s immune reaction to the vaccine is best between 9 and 14 years of age.
For further information please call your local Public Health Unit on 1300 066 055 or visit the New South Wales Health website www.health.nsw.gov.au
1.Leung TF, Liu AP, Lim FS, et al. Comparative immunogenicity and safety of human papillomavirus (HPV)-16/18 AS04-adjuvanted vaccine and HPV-6/11/16/18 vaccine administered according to 2- and 3-dose schedules in girls aged 9-14 years: Results to month 12 from a randomized trial. Human Vaccines and Immunotherapeutics 2015;11:1689-702.
2. Romanowski B, Schwarz TF, Ferguson LM, et al. Immunogenicity and safety of the HPV-16/18 AS04-adjuvanted vaccine administered as a 2-dose schedule compared with the licensed 3-dose schedule: results from a randomized study. Human Vaccines 2011;7:1374-86.
3. Romanowski B. Sustained efficacy and immunogenicity of the human papillomavirus (HPV)-16/18 AS04 adjuvanted vaccine: analysis of a randomised placebo controlled trial up to 6.4 years. Lancet 2009;374:1875-85.
This article was first published on NSW Health Government Website.