HPV causes around 70% of cervical cancers
Eight in 10 girls say that having the HPV jab makes them think twice about the risks of having sex, a poll finds.
The findings may go some way to dispel concerns that the cervical cancer vaccine could make girls more likely to start having sex younger, say experts.
But 14% of the 500 girls surveyed and who had been offered the vaccine said they might take more sexual risks because of it.
The findings are published in the British Journal of Cancer.
One in five of the 12 and 13-year-olds polled by the University of Manchester team thought the vaccine was embarrassing because it is for a sexually-transmitted infection - human papillomavirus, or HPV.
But, 79% of the girls said having the vaccination reminded them of the possible risks of sexual contact and 93% said it showed they were serious about their own health.
The survey was funded by GlaxoSmithKline, which makes the Cervarix vaccine currently used in a national immunisation programme.
The girls, from the Manchester area, were questioned before the vaccine was available nationally.
It is the first survey to focus on girls' views of the vaccine rather than asking their parents for their thoughts.
Almost four in five girls said they discussed the decision to have the vaccine with their parents and, of those girls whose parents refused the vaccine, 42% actually wanted it.
But one in 10 girls receiving the jab did not want it.
Dr Lesley Walker, director of cancer information at Cancer Research UK, said: "Despite the scare-stories, this research suggests that the HPV vaccine could make the majority of girls more cautious about sex.
"The HPV vaccine is an important step towards preventing cervical cancer in the UK but it will only be truly successful if uptake is high.
"It's important that girls also get appropriate sex education so that they're all aware of the risks of sex."
Each year around 2,800 British women are diagnosed with cervical cancer and more than 1,000 die from the disease.
Some 70% of 12-to-13-year-olds in England have been fully vaccinated against cervical cancer in the first year of the programme.
A Department of Health spokeswoman said attitudes may have changed since the vaccination campaign was rolled out.
She said: "We would always recommend involving the girl's family in the decision on whether to have the vaccine."