Question

Some individuals do not believe in taking vaccines, and thus do not get vaccinated. Very seldom do these individuals contract the diseases targeted by the vaccine. Write out a correct explanation of why these individuals do not generally contract these diseases.

Answer 1

1. Such individuals compared to other populations, carry more of a kind of natural killer cells that can detect and terminate infections at an early stage.They may have acquired the activating KIR (killer cell immunoglobulin-like receptors) genes as a result of natural selection to survive the environmental challenges .
2. Genes that control the immune response are generally variable among individuals, and such difference has been implicated in human health and disease
3. White blood cells, or leukocytes, are cells of the immune system defending the body against disease by identifying and killing pathogens and tumor cells. The main types of WBC are T lymphocytes, B lymphocytes, macrophages, neutrophils and natural killer cells. The defense in the first week of infection is mediated primarily by macrophages, neutrophils and natural killer cells. In most cases, these cells do a great job of keeping people healthy and preventing infections. If the infection is not contained by the first week, the T and B lymphocytes will initiate more specific and strong defense.
4. Macrophages, neutrophils and natural killer cells have long been regarded as primitive and nonspecific. However, recent research revealed an unexpected complexity and sophisticated capability of these cells in detecting and terminating infections at the early stage. Particularly, the natural killer cells use a family of 14 killer cell immunoglobulin-like receptors (KIR) in detecting infections and tumors – 7 of them vary greatly between individuals and involve in activating natural killer cells.