Vigor...

 

A review published in the journal Science explains the theory of "hybrid vigor immunity" in which the combination of natural immunity and vaccine-generated immunity results in a "larger-than-expected immune response." 

For the concept of hybrid immunity, the combination would be of two types of stimulation to the immune system in the forms of natural infection and vaccination.

The authors of the review suggest that this could happen with immunity because a broader range of immune cells, including both B and T cells, could get activated.

"With prior infection, their antibodies are able to recognize numerous variants, but with the addition of the vaccine, they are able to generate a large number to have a stronger effect against the virus."  

"Hybrid immunity, timing seems to be an important factor." What we have seen is that waiting six months does mount a better immune response later,"  "It seems that our immune system likes to rest and develop antibodies, and then mount a stronger response when it sees the same pathogen again later on."

When large cities that insists to get larger, here is some plan. Just a thought.