The main objectives of this study are:
- To evaluate the efficacy of carrageenan in reducing type-specific anal HPV incidence, i.e., in preventing infections by new HPV types in sexually active men who have sex with men.
- To evaluate the efficacy of carrageenan in reducing type-specific anal HPV prevalence, i.e., in accelerating clearance of existing infections in sexually active men who have sex with men
- To compare the efficacy of carrageenan for type-specific prevention and clearance of anal HPV infections among men who have sex with men with and without HIV, i.e., to evaluate whether carrageenan is equally effective among these subgroups
- To assess the safety and tolerability of the proposed gel and patient adherence to the intervention, i.e., the parameters important for future clinical use.