A committee made up of 10 experts from different medical specialties and led from the Preventive Medicine and Epidemiology Department of Vall d'Hebron by Dr. Magda Campins and Dr. Xavier Martínez-Gómez, have developed the first International Guide of recommendations based on levels of evidence for vaccination against human papilloma virus (HPV) in high risk populations. The work to prepare these recommendations is included in a study published in https://www.eurosurveillance.org/content/10.2807/1560-7917.ES.2019.24.7.1700857" Eurosurveillance.The professionals who have participated in the Guide, the first in the world to be published on vaccination against HPV in high risk population, are members of the Preventive Medicine and Epidemiology, Infectious Diseases, Digestive and Paediatric Oncology and Haematology Services. of Vall d'Hebron, the Research Program on Cancer Epidemiology of the Catalan Institute of Oncology -IDIBELL CIBER of Epidemiology and Public Health (CIBERES), and the Oncology Gynecology Unit of the Clinical Institute of Gynecology and Obstetrics and Neonatology (ICGON) of the Hospital Clínic.Human papillomavirus is the leading cause of cervical cancer and other genital cancers. Therefore, it can be found in carcinogenic and precancerous lesions of vulva, vagina, penis and anus, and also in an increasing number of oropharyngeal cancer cases. It is also the causative agent of recurrent genital warts and respiratory papillomatosis. About 90% of HPV infections in women are resolved spontaneously without any type of medical intervention. However, in 10% of the cases, the infection persists and 1% of these women will eventually develop HPV-related cancer.Vaccination against HPV is an effective primary intervention to prevent HPV infection and the burden of associated disease. There are currently three vaccinations against HPV: bivalent, for genotypes 16 and 18, quadrivalent, for genotypes 6, 11, 16 and 18, and nonavalent, for genotypes 6, 11, 16, 18, 31, 33, 45, 52 and 58.There is consensus worldwide regarding the systematic vaccination of adolescents against HPV, which was introduced in the State just over a decade ago. But, "despite the growing interest in extending vaccine recommendations for patients with high risk of HPV infection and developing related neoplasms, specific information is scarce and the recommendations for selective vaccination differ between countries", explains Dr. Xavier Martínez-Gómez, doctor of Preventive Medicine and Epidemiology Department of the Vall d'Hebron University Hospital.With this work "we have established some recommendations based on different levels of evidence (according to the GRADE scale) based on the risk of infection and pathology associated with HPV in these risk groups and also according to the evidence available on immunogenicity, safety and efficacy of vaccines in high-risk populations", says Dr. Magda Campins, Head of Preventive Medicine and Epidemiology Department of the Vall d'Hebron University Hospital and head of Epidemiology and Public Health Research Group of the Vall d'Hebron Research Institute (VHIR). In this way, the Guide will become a tool of great use for all the professionals that treat these patients.Which are the high-risk groups?The committee of experts defined as high-risk groups HIV-infected patients, men who have sex with other men (MSM), Those affected by inflammatory bowel disease, women with dysplastic cervical lesions, patients with congenital bone marrow failure syndrome, primary immunodeficiency or survivors of childhood cancers, the recipients of a solid organ transplant or hemopoietic progenitors, patients who follow immunosuppressant or biological treatments, and people with recurrent respiratory papillomatosis.What are the recommendations of the Guide? For the realization of the study, 476 scientific publications were reviewed from January 2006 to June 2016 that have allowed them to draw up a series of specific recommendations for each risk group.In general, there was a moderate and low level of evidence, which suggests that we continue to study especially in these population groups.The Guide establishes a strong recommendation to vaccinate against HPV in patients with HIV infection between 9 and 26 years old, men who have sex with men also between 9 and 26 years old, women with dysplastic cervical lesions, patients with congenital bone marrow insufficiency syndrome, women who have received a solid organ transplant or have transplanted hemopoietic progenitors between 9 and 26 years old, and patients with a diagnosis of recurrent respiratory papillomatosis. In other situations, the recommendation is weak.