Because this is a new medication, we cannot expect to have a blueprint handed down to us as to what will happen. Instead, we need to understand in more generic terms (for example, how our bodies respond to any foreign substance), and learn from it in order to make future treatments safer and better timed. Our immune systems were designed to protect us from foreign substances, often by rejecting them.
Here is what we know about how the current covid-19 vaccines influence our immune systems:
Most of the immune activation is related to structure of the spike protein in the envelope of the coronavirus. Some of the response is to the vector which carries the antigenic unit – for example the cold virus.
The level of immune protection and timing of immune response may vary between the different brands. But we know that it takes 2 weeks for the immune system to get fully activated, when it is newly exposed. With prior exposure (previous infection, second dose of vaccine) the activation is more rapid.
Either way, the immune system is likely to be most stimulated after 2 weeks of vaccination, and to reach somewhat stable states of activation after 4 weeks. A full explanation of Covid-19 vaccines, is on the Centers of Disease Control website here.
