Immune response to SARS-CoV-2 variants: A focus on severity, susceptibility, and preexisting immunity

• Main Authors: Eman Alefishat (Author), Herbert F. Jelinek (Author), Mira Mousa (Author), Guan K. Tay (Author), Habiba S. Alsafar (Author)
• Format: Book
• Published: Elsevier, 2022-02-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.
• Notes: 1876-0341; 10.1016/j.jiph.2022.01.007
• Keywords: COVID-19; SARS-CoV-2; Severity; Cross-reactivity; Antibody-dependent enhancement (ADE); Variants of concern; Infectious and parasitic diseases; RC109-216; Public aspects of medicine; RA1-1270
• Source: Journal of Infection and Public Health, Vol 15, Iss 2, Pp 277-288 (2022)

The heterogeneous phenotypes among patients with coronavirus disease 2019 (COVID-19) has drawn worldwide attention, especially those with severe symptoms without comorbid conditions. Immune responses to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the causative virus of COVID-19, occur mainly by the innate immune response via the interferon (IFN)-mediated pathways, and the adaptive immunity via the T lymphocyte and the antibody mediated pathways. The ability of the original Wuhan SARS-CoV-2 strain, and possibly more so with new emerging variants, to antagonize IFN-mediated antiviral responses can be behind the higher early viral load, higher transmissibility, and milder symptoms compared to SARS-CoV and are part of the continued clinical evolution of COVID-19. Since it first emerged, several variants of SARS-CoV-2 have been circulating worldwide. Variants that have the potential to elude natural or vaccine-mediated immunity are variants of concern. This review focuses on the main host factors that may explain the immune responses to SARS-CoV-2 and its variants in the context of susceptibility, severity, and preexisting immunity.