Immunology of HPV Infection and Vaccination: Progress and Challenges

Human papillomavirus (HPV) infection disproportionately affects both men and women, and causes a wide range of diseases from benign lesions, such as genital warts, to more serious diseases such as anogenital cancers. They are also responsible for an increasing proportion of oropharyngeal cancers. Prophylactic HPV vaccines are available and are highly effective in preventing HPV infection and their associated diseases. While these vaccines do not clear existing lesions, there are a number of promising therapeutic vaccines targeting HPV-associated lesions that are undergoing clinical trials. The primary mediator of protection for prophylactic HPV vaccines is thought to be neutralising antibodies although the level required to protect remains unknown. Other immune parameters including cellular and mucosal immunity are also likely to be important for protection. Recent data from small cohort and opportunistic clinical studies have also suggested that 1 dose may be sufficient for protection, although it is not known how long this lasts. This 'reduced dose schedule' approach has the potential to make a significant impact on the HPV disease burden in many LMICs where HPV vaccines are not currently used mainly due to their high cost.

HPV is excellent in evading the host immune system. The understanding of host immune factors involved in protection, particularly at the mucosal surface, is poorly understood. This has relevance for both prophylactic and therapeutic strategies to combat this complex pathogen. New insights into the identification of novel immunological markers of protection against oncogenic and non-oncogenic HPV types are critical in the era of reduced-dose vaccine schedules. These also have important implications for optimal immune protection of high-risk groups which are particularly vulnerable to HPV infection and associated diseases. This Research Topic will focus on current concepts and state of the art knowledge on the immunology of HPV infection and immunogenicity of current prophylactic and therapeutic vaccines.

We welcome the submission of Original Research, Review and Perspective articles covering the following aspects:

· HPV pathogenesis and host immune responses
· Mucosal immunity to HPV
· Immunogenicity of current and new prophylactic HPV vaccines
· Immunogenicity of alternative HPV vaccine schedules, including extended interval and mixed schedules
· Novel immunological markers of HPV immunity following infection and/or vaccination
· Immunogenicity of HPV vaccines in high risk groups such as HIV-infected, female sex-workers and men who have sex with men
· Immunogenicity of reduced-dose HPV vaccine schedules
· Immunology of therapeutic HPV vaccines