Will the gardasil9 hpv vaccine protect us from hpv infection for more than 16 years?

Disease is dependent on the virulence of the infectious agent and the immune system. So in general -yes But not 100%

Gardasil 9 is now available (in the USA) from ages 9 to 45 years of age in 2 or 3 doses depending on age and dose intervals. I agree, no vaccine is perfect. There needs to be more research for this over time. This is the only vaccine to prevent cervical/vaginal/vulvar cancer caused by HPV