Among girls aged under 18 years, rates of high grade cervical abnormalities (HGAs) halved after the country introduced a national HPV vaccination programme in 2007.

Experts said the findings were encouraging but needed validating before the link could be proven.

In the UK, there has been a national programme to vaccinate girls aged 12 to 13 against HPV since 2008, with a catch-up campaign for girls aged 14-17.

From September 2008 to July 2010, at least four million doses of bivalent HPV vaccine Cervarix were given.

The DoH is deciding which vaccine to use for the next stage of the UK’s programme. This could see Cervarix replaced by Gardasil, which also protects against genital warts.

The study by researchers at the Victorian Cytology Service in Victoria, Australia and published in The Lancet is the first to examine the effects of a national HPV vaccine programme on  the rate of cervical abnormalities.

HPV types 16 and 18 account for the majority of cervical cancers and many precancerous cervical changes.

Australia was the first nation to roll out a widespread HPV vaccination programme in April 2007 and used the Gardasil vaccine.

All women aged 12-26 were invited to be vaccinated over the next two years.

Researchers tracked the rate of high- and low-grade abnormal cervical lesions detected among women of these ages over time.

Before the programme, there were 80 cases of HGAs among teenage girls for every 10,000 vaccinated.

This fell to 42 per 10,000 in the years after the vaccination campaign began.

However, no decline was seen for low grade lesions or in older age groups.

The authors said: ‘Our finding that the decrease in HGA incidence occurred in the youngest vaccination cohort before it occurred in the older, catch-up cohorts – who were more likely to have been previously sexually experienced – reinforces the appropriateness of the targeting of prophylactic HPV vaccines to preadolescent girls.’

In an editorial, Dr Mona Saraiya and Dr Susan Hariri of the Centers for Disease Control and Prevention in Atlanta, Georgia, said: ‘The not-so-cautious optimist in us wants to hail this early finding as true evidence of vaccine effect.’

However, individual-level vaccine status was not considered and this is needed to confirm the findings, they said.