Researchers say that while immunizing young Australian women against the human papillomavirus (HPV) with an aim to reduce cases of cervical cancer found that transmission rates for genital warts have fallen drastically.

They noted genital wart infections to have almost halved since the vaccination. In fact, number of young Australian women coming to sexual health clinics has fallen by 59 per cent. There was also a 28 per cent decline among heterosexual men.

The declines were "substantial", writes Professor Basil Donovan from the University of NSW's National Centre in HIV Epidemiology and Clinical Research.

"Until the HPV vaccination program began in July, 2007, the proportion of women and heterosexual men diagnosed with genital warts was stable," Prof Donovan said in a paper published in The Lancet.

"The decline in proportion of people with genital warts contrasted with increasing rates of chlamydia and no reported change in frequency of genital herpes."

Scientists have noted that the Gardasil vaccine prevents transmission of four strains of HPV. Two of these strains cause genital warts and two others cause cervical cancer.

Gardasil's inventor Professor Ian Frazer said it pointed to the vaccine's potency against "other HPV related disease including cervical cancer".

Dr Edith Weisberg, director of research at the Sydney Centre for Reproductive Health at Family Planning NSW, said the early "dramatic" impact raised hopes.

"It points to the likelihood of a possible equal reduction in high-grade cervical lesions and, ultimately, cancer of the cervix in this cohort of vaccinated young women," Dr Weisberg said. Anything that can reduce the negative effects of genital warts is welcome.