A study has found the cost and effort to roll out the national HPV vaccination programme was "well worth it" and has had a "marked" effect on HPV-related cancer rates.

University of Otago obstetrics and gynaecology associate professor Peter Sykes led a study researching the effectiveness of the national HPV vaccination programme.

The Christchurch-based study revealed the programme, running since 2008, has reduced cervical cancer by more than two-thirds - and showed the vaccine was "incredibly important and makes a real difference".

"It's about a two-thirds reduction, a little bit more than two-thirds, 70 per cent. If we compare that to wearing a seatbelt which halves your risk of a serious injury in a road traffic accident, it's a very effective intervention."

The study, published in the Journal of the Royal Society of New Zealand, found that vaccine prevents not only cervical but also other HPV-related diseases - including cancers of the mouth and throat.

It also showed a greater benefit for those vaccinated at a young age, before sexual activity, Sykes added.

"What we really need to do is improve our vaccination rates in that cohort of people. We currently vaccinated about 60 to 65 per cent of people. But the [World Health Organisation wants] 90 percent of people.

"We need to invest further to meet the goal of eradicating cervical cancer as a public health problem for all."