This was true before COVID-19.
It's called herd immunity.
Immunity comes on a sliding scale of "none to perfect" immunity. But no one has perfect immunity.
You getting sick has to do with the acute exposure to the virus. How much of a viable virus ends up in your respiratory system determines whether or not you will get sick.
If you are exposed to enough of the virus, in a very short period of time, no matter how good your immune system is, you will get ill.
Most vaccines give you moderate immunity. Almost no vaccine gives you perfect immunity (assuming perfect health).
This was true before COVID-19.
It's called herd immunity.
Immunity comes on a sliding scale of "none to perfect" immunity. But no one has perfect immunity.
You getting sick has to do with the acute exposure to the virus. How much of a viable virus ends up in your respiratory system determines whether or not you will get sick.
If you are exposed to enough of the virus, in a very short period of time, no matter how good your immune system is, you will get ill.
Most vaccines give you moderate immunity. Almost no vaccine gives you perfect immunity (assuming perfect health).
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