“The vaccines were always designed to focus against disease in the lower airways [the lungs] — not in the upper airways [the nose and upper throat],”
Think about that. According to Dr. Barney Graham, deputy director of the Vaccine Research Center at the National Institute of Allergy and Infectious Diseases—-a person becomes severely ill when the virus enters the lungs, and that is exactly where the vaccines offer up their most protective barrier.
You see, the vaccines trigger the creation of immunoglobulins, which are proteins that function as antibodies. The main one generated by the vaccines is immunoglobulin G (IgG) which easily moves from the blood into the lower airways (the lungs) where it can block the virus. The level of IgG in blood needed to penetrate the tissues of the upper airways (the nose and throat) is much higher and that is why it is more difficult to block the virus from growing in the nose.
“That’s why we see such consistency in the efficacy against severe disease. It wasn’t designed to protect the upper airways as much,”