Abstract
In 2019, the novel coronavirus, SARS-CoV-2, caused a worldwide pandemic, affecting more than 630 million individuals and causing 6.5 million deaths. In the general population, poorer outcomes have been associated with older age, chronic lung and cardiovascular diseases, and lymphopenia, highlighting the important role of cellular immunity in the immune response against SARS-CoV-2.
Moreover, SARS-CoV-2 variants may have a significant impact on disease severity. There is a significant overlap with complications commonly found in inborn errors of immunity (IEI), such as primary antibody deficiencies.
The results of various studies have provided ambiguous findings. Several studies identified risk factors in the general population with a minor impact on SARS-CoV-2 infection.
However, other studies have found a significant contribution of underlying immunodeficiency and immune-system dysregulation to the disease course. This ambiguity probably reflects the demographic differences and viral evolution.
Impaired antibody production was associated with prolonged viral shedding, suggesting a critical role of humoral immunity in controlling SARS-CoV-2 infection. This may explain the poorer outcomes in primary antibody deficiencies compared to other IEIs.
Understanding coronavirus disease 2019 (COVID-19) pathogenesis and identifying risk factors may help us identify patients at high risk of severe COVID-19 for whom preventive measures should be introduced.