(HealthDay News) — Girls who receive the quadrivalent human papillomavirus (HPV) vaccine before 17 years of age can get considerable protection from condyloma after two doses, although maximum protection is observed after the recommended three doses, according to a study published in the February 12 issue of the Journal of the American Medical Association.
Eva Herweijer, from the Karolinska Institutet in Stockholm, and colleagues assessed the incidence of condyloma among 1,045,165 females (10–24 years old) living in Sweden who received the quadrivalent HPV vaccine.
The researchers identified 20,383 cases of condyloma during follow-up. Among those who were first vaccinated at 10–16 years of age, the incidence rate ratio was 0.31 for one dose, 0.29 for two doses, and 0.18 for three doses. Compared with no vaccination, per 100,000 person-years, the incidence rate difference was 384 for one dose, 400 for two doses, and 459 for three doses.
“Although maximum reduction in condyloma risk was seen after receipt of three doses of quadrivalent HPV vaccine, receipt of two vaccine doses was also associated with a considerable reduction in condyloma risk,” Herweijer and colleagues conclude.
Several authors disclosed financial ties to pharmaceutical companies, including manufacturers of HPV vaccines.