[The 2-dose schedule of HPV vaccines in young adolescents]

To summarize new knowledge about the 2-dose HPV vaccine schedule in young adolescents.

Review article.

Department of Gynaecology and Obstetrics, First Faculty of Medicine, Charles University and Hospital Na Bulovce in Prague; Oncogynaecological Center, First Faculty of Medicine, Charles University and General University Hospital in Prague.

The goal of immunization programs in many countries is the prevention of cervical cancer using either the bivalent or the quadrivalent HPV vaccine. The vaccines, which were designed to prevent cervical cancer outcomes in adults, need to be administered before the onset of sexual activity. Since the HPV vaccines are among the most expensive of all the widely recommended vaccines, limited financial resources restrain the HPV vaccination in some countries around the word. Higher immunogenicity of both HPV vaccines in young adolescents, as well as potential cost savings, have prompted discussions about the efficacy of the 2-dose HPV vaccine schedule. Results of the immunobridging studies showed that two doses of the bivalent and the quadrivalent HPV vaccine in young girls induced geometric mean antibody titers that were non-inferior to geometric mean antibody titers elicited in older girls and women with three doses of the same vaccine. Non-inferiority for HPV-16, -18, -31 and -45 was obtained for the 2-dose of the bivalent HPV vaccine in girls 9-14 years old in the period of 48 months and for HPV-6, -11, -16 and -18 for the 2-dose of the quadrivalent HPV vaccine in girls 9-13 years old in the period of 36 months.

These results indicate that the bivalent and the quadrivalent vaccine HPV vaccine applied in 2 doses has sufficient immunogenity in young girls.