You are playing semantics.
Vaccinations greatly reduce the probability of infection*, serious illness, hospitalization and death from COVID.
The gap in infections, serious illnesses, hospitalizations and deaths between for vaccinated v unvaccinated individuals is what the vaccines have prevented.
*For the record: No vaccine prevents infection, pick any vaccine for any virus; the virus has to enter the body (infect the body) before the immune system starts to fight it.
Infection is not the measure of a vaccine’s success, vaccines are measured on their ability to prevent the diseases that arise when the infection gets past the immune system.
Infection is not the same thing as disease.
https://www.who.int/news-room/feature-stories/detail/vaccine-efficacy-effectiveness-and-protection
https://www.mayoclinic.org/diseases-conditions/infectious-diseases/in-depth/germs/art-20045289