Can the vaccine prevent virus spread to the non-immune? Understanding "Compartments" of immunity

It is very awkward for me to do this, but to lend credibility to what I have written below, I will state my background. I have a doctorate degree in immunology from The University of Notre Dame. I spent a career at the National Institutes of Health and in the pharmaceutical/biotechnology industry studying the regulation of the immune response. I have authored or co-authored over 70 scientific research publications on the same. Enough said.

In the past two years, I have spent hundreds of hours monitoring and studying scientific reports on the COVID virus, and the immunities that develop following either vaccination with the mRNA vaccines or following an infection with the virus. I now feel compelled to state some facts based on our understanding about what the immune system can do and what it cannot do.

There are many differences between vaccine-induced and infection-induced immunities. What I have written here pertains to only one aspect of those differences---namely, the ability of those two very different immune responses (vaccine versus infection) to reduce subsequent transmission of the virus to non-immune people. This is an important issue because the prevention of virus spread is the primary reason for vaccine mandates.

It has been well-understood for decades and modern immunology textbooks make it clear that we have two almost completely “compartmentalized” and independently functioning segments of the immune system. This “compartmentalization” has profound implications for the question about the vaccine and virus spread.

The first segment or compartment is the immune system of, principally, the blood stream, lymph nodes, lymph vessels and the spleen. This is called the Systemic Immune System (SIS). The SIS is designed, for the most part, to prevent/reduce infection of the internal organs. The SIS is stimulated to produce the circulating antibodies that appear in the blood stream after a systemic infection (including a clinical COVID infection) or after the administration of an intramuscular vaccine like the COVID vaccine.

The second segment or compartment of the immune system is dedicated to the linings (mucosa) of both the respiratory tract or airways (nasal passages, trachea, bronchi, alveoli, etc.) and the intestines. This second immune system is actually larger in immune capacity than the SIS, described above.

Mother nature gave us this very large immune capacity because of the huge number of different disease-causing pathogenic organisms that infect us through either our airways or intestines; bacteria, viruses and parasites---from anthrax to smallpox, the mumps to dysentery. Putting the intestinal lining aside and focusing on the airways, the linings are made up of so-called mucosal cells (secrete mucous) that have their own private (“compartmentalized”) set of immune cells (lymphocytes) right there in the linings of the airways. These mucosal-associated lymphocytes provide the first line of defense following an airway infection such as with the COVID virus.

Next week in the Pathfinder, I will describe the mechanism by which the mucosal immunity functions through a very special class of antibody molecules. That description will allow us to answer the question about the vaccine and the person-to-person spread of the virus.