Fig. 1.

Evolution of SARS-CoV-2 infection. The diagram shows the arrangement of the course of SARS-CoV-2 infection and the immune response measured by antibodies. Also, the following has been added: (A) Siddiqi’s and Mehra’s¹⁰ proposal of clinical stages and the evolution of adaptative immune response mediated by antibody production and the evolution of a common viral infection. Siddiqi and Mehra propose a clinical staging system in 3 different stages to facilitate the use of a uniform nomenclature. Thus, they propose a stage i or early infection stage, a stage ii or pulmonary stage, and a stage iii or hyperinflammatory stage together with potential treatment in each stage. However, this is somehow different from the body’s immune response to viral infection (B). In this bodily response to a viral infection, the innate immune response kicks in right at the beginning of the infection until the adaptative immune response is built with the production of antibodies just a few days later. Thus, some drugs used to treat COVID-19 block interleukin-1 that activates T cells or interleukin-6 that participates in B-cell maturation, the cells that will eventually build the antibodies.