The study, which monitors infectious diseases in the UK, has followed government health advisers' recommendation that pre-pubescent girls should be vaccinated against the sexually transmitted virus.
The agency tested blood samples from 1,483 girls and women aged 10-29 years for types of the virus that can cause genital warts and cervical cancer.
The results, presented at the agency's annual conference in Warwick today, revealed that the risk of infection rises sharply from the age of 14. Presenting the findings, Dr Andrew Vyse, of the HPA was quoted: "This study gives us vital information about how common HPV infection is in young women of different ages." At the same time, he cautioned that more research was needed to "learn more about the risks of infection and of the risks for persistent infection and progression to cancer".
Juliet Hillier, of the sexual health charity Brook, said the findings demonstrated "a real need to improve education and prevention programmes which target young people". "The government must urgently implement a vaccination programme for girls and boys before they become sexually active and ensure resource is available to do so", Hillier said.
Meanwhile, a separate study published by the Health Protection Agency today said that up to 70% of cases of cervical cancer and 95% of cases of genital warts in men and women could be prevented by setting up a national HPV immunization programme. The lead researcher Mark Jit reported: "The benefits to health would be worth the cost of vaccination if our model assumptions are correct."
In June, the Department of Health had informed that a HPV vaccine for girls aged 12 to 13 in three doses over a six-month period would cost around Ģ300. Its agreement "in principle" to providing the jab followed a recommendation from the Joint Committee on Vaccination and Immunization (JCVI). The jab would not be compulsory but would be offered to girls in all parts of the UK.
There are two HPV vaccines that could be used in an immunization programme: Gardasil, made by Merck and Sanofi Pasteur, and Cervarix, made by GlaxoSmithKline. HPV jabs have been approved in dozens of other countries, including the US, Canada and Australia.
If a vaccination programme was introduced, cervical smear testing would need to be continued for a long while, partly because the jab only protects against the two most common strains of HPV, which account for 70% of cervical cancers.
Each year around 2,800 British women are diagnosed with cervical cancer and more than 1,000 die from the disease.
Around 200,000 women a year also have pre-cancerous changes to their cervix picked up through smear tests. Some HPV infections can cause cervical cancers in women and genital warts in both women and men, although most infections with HPV cause no symptoms and clear on their own.