Vaccination is being mandated as mandatory so that herd immunity be achieved. Herd immunity is known as population immunity. In general, it is the indirect protection from an infectious disease that arise when a population is immune either through vaccination or immunity developed over past infection. But the health experts supports accomplishing herd immunity through vaccination and not allowing a disease to transmit through any segment of the population because it would end in futile cases and deaths.
The antibodies the body produce is the same as the antibodies produce by our immune systems to fight disease either through vaccination or when we are exposed to a disease. The only difference is vaccines work without making us sick.
To achieve herd immunity, a substantial part of the population need to be vaccinated so that the overall amount of virus to spread will be lowered.