An Australian success story: the HPV vaccine

9 January 2017 | Adjunct Professor Karen Canfell

Teenage girl recieving HPV vaccine_1200

Image courtesy of University of Queensland Faculty of Medicine.

We have now reached a huge milestone in cervical cancer prevention: every woman in Australia aged 35 years and younger is better protected against HPV than ever before. HPV – the human papilloma virus – is the cause of virtually all cervical cancers, so this is a truly remarkable feat.

University of Queensland researcher and 2006 Australian of the year Professor Ian Frazer first started developing a vaccine for HPV in the 1990s, along with his colleague, the late Dr Jian Zhou.

In 2006, the TGA approved Gardasil, and only a year later, Australia became the first country that rolled out a national HPV vaccination program. In 2013, the Australian government extended the vaccination program to include teenage boys.

 

The impact of the HPV vaccine

In the decade since its commercial release, the HPV vaccine has significantly lowered the risk of HPV-related cancers for thousands of women around the world, with over 200 million doses distributed in 130 countries to date.

The HPV vaccine has been extremely effective. In girls and young women aged nine to 26, the vaccines have been proven to protect against two types of HPV that cause about 70 per cent of cervical cancers (if women have not already been exposed to these types), and two more types that cause about 90 per cent of genital warts. The vaccine also protects against about 70 per cent of vaginal cancer cases and up to 50 per cent of vulva cancer cases.

Just to give you an idea of the impact the vaccine has had – in the first four to five years after the program started, we observed a 77 per cent decrease in the number of 18-24-year-old women with HPV (for the HPV types covered by the vaccine). Precancerous abnormalities also decreased – by 34 per cent in 20–24 year-olds, which means they will be at a much lower lifetime risk of ever developing cervical cancer. There was also a marked decline in anogenital warts in women in their early 20s, and a decline in the rates of genital warts in young heterosexual men, even before they were included in the vaccination program.

 

Next-generation protection – HPV-based screening

Looking ahead, cervical cancer prevention in Australia will become even more effective, driven by a switch to HPV-based screening, and the potential introduction of a next-generation vaccine.

In 2017, the national screening program will be renewed. Key changes include:

  • A new test: the screen will no longer look for abnormal cells (like the Pap test did), but instead detect HPV infections directly
  • A change in interval, from 2- to 5-yearly testing
  • A change in starting age, with the first test at age 25, rather than age 18-20

The new program is estimated to lower cervical cancer incidence and mortality by at least 20 per cent – thanks to the more accurate, effective and safer test.

Exciting research will look at how this new system compares with previous screening: Compass is the first ever large-scale clinical trial to assess screening tests in a population of women who have received the HPV vaccine. Cancer Council NSW conducts the trial in partnership with the Victorian Cytology Service, and we hope to be able to present results from the first phase soon.

 

A new HPV vaccine

The good news doesn’t stop here – a new HPV vaccine is on the horizon. The new vaccine has recently become available and has been approved for use in the USA and Europe. In Australia, the new vaccine is expected to be reviewed for inclusion on the National Immunisation Program Schedule over the next year or so.

There’s a range of recent and upcoming research that predicts and estimates the effect that the new form of the vaccine will have in Australia. For example, recent research by Cancer Council NSW looked at how the next-generation vaccine will further reduce cervical cancer diagnosis and death in Australia.

Our study found that the switch to HPV screening alone reduces someone’s lifetime risk of cervical cancer by at least 18-20 per cent, compared to the current Pap test program – even if they’re not vaccinated.

Girls who have been given the current vaccine are predicted to experience an additional reduction of 54 per cent. Those who will receive the next-generation vaccine in the future are estimated to experience a reduction of another 11 per cent. Girls offered either vaccine are also at substantially lower risk of precancer treatment.

Australia has the best cervical cancer prevention program in the world, and the future vaccine – combined with the renewed screening program that comes into place in December 2017 – will help us save even more lives, and eventually even eradicate cervical cancer.

 

Summary of key points

  • In 2007, Australia became the first country to roll out a national HPV vaccination program.
  • In 2013, boys were included in the program, too.
  • 200 million doses have been distributed to date, in 130 countries.
  • The current vaccines protect against about 70 per cent of cervical cancers, 90 per cent of genital warts, 70 per cent of vaginal cancer cases and up to 50 per cent of vulva cancer cases.
  • In the first four to five years after the program started, HPV infections of the types that are included in the vaccine decreased by 77 per cent in 18–24-year-olds.
  • Precancerous abnormalities decreased by 34 per cent in in 20-24-year-olds.
  • The next-generation vaccine prevents persistent infection and precancerous lesions associated with nine different HPV types. Seven of these types cause cancer and are together found in around 90 per cent of cervical cancers worldwide.
  • It will further improve protection and lower rates of HPV-related cancers, especially cervical cancer.