According to the results of a long-term study organized by the manufacturing company MERCK SHARP & DOHME, Corp., the 4-valent vaccine against human papillomavirus (HPV) Gardasil when administered to preadolescence and adolescence remain effective, at least for at least 8 years, and there is no need for a booster dose.

Gardasil vaccine, containing HPV antigens (L1 protein) types 6, 18, 11 and 16, appeared on the pharmaceutical market in 2006. HPV vaccine effectively prevents neoplasia of the cervix, vagina and organs external genital as well as anogenital warts in vaccinated girls. at the age of 16-26 years.

The August issue of Pediatrics published the results of a long-term study of the immunogenicity, efficacy and safety of the 4-valent HPV vaccine.

The study included adolescents (boys and girls, n = 1781) aged 9 to 15 years who had no sexual experience, who were divided into a 2: 1 ratio to receive an HPV vaccine or a placebo according to the scheme of 0, 2 and 6 months. After 30 months, patients in the placebo group (n = 482) received the HPV vaccine according to the same schedule, then the two cohorts of patients were observed until month 96. Patients over 16 years of age were able to assess effectiveness.

The main objective was to assess the levels of antibodies against HPV types 6, 11, 16 and 18 antigens. The secondary objective was to assess the efficacy of the vaccine against diseases associated with HPV types 6, 11, 16 and 18.

For each of the 4 HPV antigens included in the vaccine, the anti-HPV response induced by the vaccine persisted until month 96. Among the 429 patients who received the HPV vaccine, on average, 12 years, none of the patients has developed diseases caused by 6, 11, 16 and 18 types of HPV or no persistent infection has been observed for more than 12 months.

Patients who received the vaccine in the 30th month of the study (average age of 15 years) had an initial seropositivity rate similar to more than one type of HPV compared to patients vaccinated initially.

During the study, no serious adverse events were observed in boys or girls.

Thus, the 4-valent vaccine against the human papillomavirus Gardasil offers clinically effective protection and causes the development of a significant long-term protective titer of antibodies for 8 years.