Women who receive human papillomavirus (HPV) vaccines are gaining long-term protection against cervical cancer-causing HPV infections, a study at the Women’s has found.
There are more than 200 HPV types. Some can be spread through sexual contact and cause cervical, anal, oral and other cancers. Young people are at highest risk of HPV infection within months to a few years of becoming sexually active.
In 2007, Australia became the first country to implement a national HPV vaccination program in schools. A catch-up service was also offered to women aged up to 26 years, in the program’s first two years.
The vaccine prevents infection with HPV16 and 18, which cause approximately 70 per cent of cervical cancers. High uptake has led to greater than 90 per cent of population-level reductions in the prevalence of these HPV types in women aged under 35.
Lead Researcher Dr Dorothy Machalek said the study measured the prevalence of vaccine-preventable and non-vaccine preventable HPV types. It also documented risk factors for HPV infection in the context of a highly vaccinated population.
A total of 1,564 women aged 18-35 years participated in the study. When they attended health services nine to 12 years after the introduction of the vaccine program, they agreed to give a sample for HPV testing and completed a short questionnaire on risk and lifestyle factors.
“We found that overall prevalence of vaccine-preventable HPV types was very low,” Dr Machalek said.
“However, we found that HPV types, particularly those not targeted by the vaccine, continue to be commonly detected in young women,” she said.
“When assessed by vaccination status, we found that unvaccinated women were more likely than their vaccinated colleagues to be positive and had eight-fold higher HPV levels compared to vaccinated women.
She said the results highlighted the need to continue efforts to increase vaccine coverage, and the importance of cervical cancer screening for eligible women.
This research was published in Vaccine.