[Amezarak]

We knew the odds the Covid vaccine would substantially reduce transmission were very low. Covid first impacts your mucosal immune compartment, which means an infection first gives you all the symptoms exhibited by a mild case of Covid. It also mostly spreads from there as you exhale.

The vaccine does not target your mucosal immune system. It's injected. Thus, the vaccine will help you if you develop a severe case of Covid that spreads beyond your throat/sinuses/lungs. Immune system compartments work largely independently. [1]

[1] https://www.ncbi.nlm.nih.gov/books/NBK27169/

> The first is that immune responses induced within one compartment are largely confined in expression to that particular compartment. The second is that lymphocytes are restricted to particular compartments by expression of homing receptors that are bound by ligands, known as addressins, that are specifically expressed within the tissues of the compartment. (Immunobiology: The Immune System in Health and Disease. 5th edition.)