Schoeman, DewaldFielding, Burtram C.2021-10-152021-10-152021Schoeman, D., & Fielding, B. C. (2021). Leptin deficiency, caused by malnutrition, makes you susceptible to sars-cov-2 infection but could offer protection from severe Covid-19. mSphere, 6(3), e00031-21, 1-6. 10.1128/mSphere.00031-212379-504210.1128/mSphere.00031-21http://hdl.handle.net/10566/6916In much of the developing world, severe malnutrition is the most prevalent cause of immunodeficiency and affects up to 50% of the population in some impoverished communities. As yet, we do not know how severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) will behave in populations with immunodeficiency caused by malnourishment. Interestingly, researchers are now speculating that, in some instances, a defective cellular immune system could paradoxically be a protective factor against severe disease in certain patients contracting SARS-CoV and SARS-CoV-2. This could be linked to the absence of T-cell activation. Based on available information presented here, it is plausible that the hyperimmune response, and subsequent cytokine storm often associated with severe coronavirus disease 2019 (COVID-19), could be “counteracted” by the defective immune response seen in individuals with malnutrition-induced leptin deficiency. In this paper, we proposed a theory that although those with malnutrition-linked leptin deficiency are at risk of SARS-CoV-2 infection, they are at lower risk of developing severe COVID-19.enCovid-19UndernutritionLeptin deficiencyCytokine stormMalnutritionArticle