Teenage girls who are most at risk of developing cervical cancer are least likely to be offered a protective jab against the disease, researchers have claimed.
Those who are higher risk are also less likely to complete the full course of the HPV vaccination - which protects against the human papilloma virus.
In 2008 the HPV vaccination programme was launched in England to vaccinate girls aged 12-13 to help prevent cervical cancer.
But experts have called for more to be done to encourage uptake of the programme.
A new research paper, published in the journal Sexually Transmitted Infections, examined more than 2,200 teens aged 13 to 19 who attended sexual health clinics in 19 hospitals and 13 community services across England between March and August 2011.
The researchers said these girls were more likely than their peers to smoke, have sex under the age of 16 and have had previous sexually transmitted infections (STIs) .
Almost three out of four of the teens said they had been offered the HPV jab and only 65% received all three vaccinations, they found.
Rates of women who received the jab were significantly lower among teens from London, those from non white ethnicities, those aged 17 to 19, smokers and those who had previously contracted an STI.
“The highest risk individuals were the least likely to have been offered or to have completed the course,” the authors wrote.
“This survey highlights an opportunity for primary prevention by routinely offering the HPV vaccine to eligible women attending sexual health services.”
A Department of Health spokeswoman said: “We encourage all 12-13 year old girls to get the HPV vaccination. They are usually given the vaccine at school but it is also available from GPs in recognition of the fact that not all schools offer the vaccine.
“The HPV vaccination programme has been a considerable success with more than six million doses given so far in the UK since 2008, and 87% of girls completing the three-dose course.”