Major Gaps and Lag Time in Immune Response to Sars-Cov-2.
A new study in the peer-reviewed journal Cell Immunity, found that multiple components of immunity are deficient and dysfunctional for prolonged periods in Covid-19 patients.
An in-depth examination of immune cell counts and immune expression in both acute and recovering Covid-19 cases (mild and severe) found reductions in the levels and effective activity of a broad range of circulating immune cells. These included reductions in T-cells, natural killer cells, monocytes and most significantly of all dendtritic cells (which are responsible for activating T-cells).
Neutralizing antibodies on the other hand, were produced rapidly and were found to be consistently abundant, however, the immune system's capacity to coordinate with the antibodies was noticeably lacking.
Many patients exhibited substantial delays in the production of useful levels of T-cells that were tailored to recognize the Sars-Cov-2 virus. Notably, in severe cases, all patients failed to develop measurable levels of T-cells that are known to be effective in targeting key features of the Sars-Cov-2 virus until at least three weeks after initial symptoms set in.
It was further identified that decreased T-cell counts were all associated with decreases in effective T-cell proliferation, hyper-activation and migration into the lungs.
Causally, the study identified that in addition to dendritic cells being depleted in acute stage Covid-19 patients, the virus also interfered with their function rendering them virtually inactive. Meaning they produced insufficient anti-viral cytokines (like interferon) and insufficiently matured to be able to alert T-cells to the virus.
The study noted that this inactivation has been found to occur when viruses infect dendritic cells themselves. Although infected dendritic cells are not capable of replicating the virus, it is critical to know that once viral particles enter the cell, it appears that they effectively go into shut down.
The data is clear, this is a smoking gun as it relates to why immunity fails in severe Covid-19 cases and therapies that work to prevent one's immune system from effectively going to sleep in this way may be the cornerstone of future treatments.