1. that we who were vaccinated were in excess of 94% (as at end CY2022). this created the optimal breaker for the virus to be contained due to broad general immunity. 2. the virus mutated, as all viruses do, to become less infectious and less lethal leaving only the oldest and most frail people to be subject to infection. one problem remains are the people who are immunocompromised due to immune system malignancy, eg, leukaemia, and those on imunno-suppressant medication.
if you can't understand this then I suggest you search and see the life cycle of viruses and viral infections.
