A) Effect of vaccination on the prevalence and distribution of Human Papillomavirus (HPV) genotypes. HPV vaccination was introduced in Spain in 2007-2008 for the prevention of cervical cancer and other cancers associated with these viral infections. The use of HPV vaccination is expected to lead to a decrease in vaccine genotypes in the population. However, it may also lead to an increase in other non-vaccine genotypes, similar to the change in vaccine serotypes observed in pneumococcal infections. This requires continuous surveillance of genotype frequency and data to monitor the efficacy of the HPV vaccination program.

B) Study of the distribution and dynamics of HPV infections in risk groups. There are some particularly vulnerable groups, some of them difficult to access (sex workers, transgender groups, etc.), in which HPV infections deserve special attention. The prevalence of HPV infection is especially high in people living with HIV and/or among men who have sex with men. Knowledge of the distribution and dynamics of infections is especially interesting in these groups, as they may help to improve current algorithms for the prevention of anogenital cancer.

C) Study of infection by HPV genotypes and their relationship with progression to neoplastic processes. The oncogenic capacity of some HPV genotypes and their involvement in the production of anogenital cancer is well known. In addition, there are other oncological processes, such as non-melanoma skin cancer, in which HPV could be implicated. Thus, members of the gamma-24 HPV species have recently been associated with skin cancer. It is to be hoped that the appearance of new genotypes and the performance of more extensive studies may lead to the identification of new associations between HPV and neoplastic processes.

D) Study of co-infections by different HPV genotypes. The presence of co-infections of different HPV genotypes is a very frequent finding, both in skin samples and in different mucous membranes. The great genetic diversity of HPV limits the ability of classical molecular methods to perform a comprehensive detection and study of the genotypes present. However, the use of massive sequencing makes it possible to eliminate some of these biases and to obtain more detailed information on the existing HPV populations, as well as to analyze interactions between the different genotypes.

E) Description of new HPV genotypes/variants. Currently at the International HPV Reference Center (Karolinska Institute, Sweden) more than 220 HPV genotypes are described, distributed in 5 different genera. However, improved molecular detection techniques, as well as the use of massive sequencing, are allowing this number to increase rapidly. The study of new genotypes and variants is essential for the validation and quality control of available diagnostic methods. Similarly, their characterization and the study of possible associations of HPV with pathologies other than those already known is a field of great interest for research.