COVID-19 vaccines are safe and effective at preventing infection, hospitalization, and death. Most people who get COVID-19 are unvaccinated. However, since vaccines are not 100% effective at preventing infection, some people who are
fully vaccinatedwill still get COVID-19. An infection of a fully vaccinated person is referred to as a “breakthrough infection.” People who get vaccine breakthrough infections can be contagious but are less likely than unvaccinated people to be hospitalized or die.
That is from the very article you linked to. Did you miss the part where it says they are "effective at preventing infection"? All infections? No. But it prevents the vast majority of infections. C'mon. At least read what you are citing.