Early Insights into Immune Responses during COVID-19

Coronavirus disease-2019 (COVID-19) is caused by the newly emerged virus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and was recently declared as a pandemic by the World Health Organization. In its severe form, the disease is characterized by acute respiratory distress syndrome, and there are no targeted intervention strategies to treat or prevent it. The immune response is thought to both contribute to the pathogenesis of disease and provide protection during its resolution. Thus, understanding the immune response to SARS-CoV-2 is of the utmost importance for developing and testing vaccines and therapeutics. In this review, we discuss the earliest knowledge and hypotheses of the mechanisms of immune pathology in the lung during acute infection as well at the later stages of disease resolution, recovery, and immune memory formation.