HPV Vaccine halves cervical cancer rates in 10 years

Dr Colin Laverty was a remarkable man; a significant art collector, educator, writer and publisher. He was also a world-renowned gynaecological cytology and histopathology specialist. His initial research into the significance of the human papillomavirus (HPV) back in the 1970s is the foundation of the world’s battle against cervical cancer today.

The University of Sydney graduate was the first person in the world to confirm that the human papillomavirus (HPV) was much more common in the cervix than previously thought and in 1978 he hypothesized that this virus could be a cause of cervical cancer.

The role of human papillomavirus in cervical cancer

Pap smears as a method for detecting cervical cancer had been around since 1928. Fifty years later, though, it was Dr Laverty who recognised that cellular abnormalities, known as koilocytes, were much more common in Pap smears than previously realised. He also noted that in the majority of cases clinical warts were absent, even on careful clinical examination.

A researcher was employed and an electron microscopic technique was devised which confirmed Laverty’s suspicion that HPV particles were present in these koilocytes. Dr Laverty was the first person in the world to publish findings that proved atypical, potentially premalignant cells in pap smears in women without actual genital warts, were papillomavirus infected. This in turn led to his hypothesis in 1978 that HPV was possibly involved in the development of cancer in cervical cells.

In the years that followed, Laverty’s suggestion that HPV could be involved in the causation of cervical cancer was confirmed. And that meant, theoretically, a vaccine could be developed against cervical cancer.

A vaccine against cervical cancer

The prospect of a vaccine against cervical cancer was significant. Unlike most viruses though, HPV cannot be cultured without living tissue, and therefore development of a vaccine was not straightforward.

In the early 1990s another legend of Australian medicine, Dr Ian Frazer, alongside Chinese virologist Jian Zhou, began work on finding a solution to this.

They used molecular biology to synthesize particles in vitro that could mimic the virus and developed this into a protein from which the HPV vaccine would ultimately be made. After three years of design they had the makings of a vaccine against HPV. In 1998 Frazer completed the first human trials for Gardasil, the vaccine still used in Australia today.

The Australian HPV Gardasil vaccination program was introduced in 2007 for young women, and in 2012 for young men, meaning younger generations of Australian women have a much lower risk of cervical cancer. The vaccine protects against HPV 16 and 18 – the two subtypes responsible for 70% of cervical cancers.

So what’s next?

At the time of Laverty’s discoveries, the only way of confirming the presence of HPV was via electron microscopy. Today, though, new methods have been developed to detect the molecular material (such as DNA) of high risk strains of HPV. And this is changing how cervical cancer screening is being undertaken in Australia.

The current screening test looks for abnormal cells in a sample taken from the cervix. Abnormal cells could indicate cancer, precancerous cells, or other changes in the body such as a virus or infection.

The new test, however, allows doctors to know if a woman is at higher risk of cervical cancer before abnormal cells can be detected, by looking for HPV DNA. Plus it can distinguish between strains that are ‘high risk’ (ones associated with cancer) and ‘low risk’ (associated with warts, for example) meaning less unnecessary follow up procedures for women not at risk of developing cervical cancer.

And we’re sure Dr Laverty would have been thrilled to learn of the latest estimates that suggest that this new test method combined with the HPV vaccination program could reduce cervical cancer rates in Australia by 15%.