Immune responses during COVID-19 infection

Area of Science:

• Immunology
• Virology
• Epidemiology

Background:

• Three novel coronaviruses (CoVs), including SARS-CoV, MERS-CoV, and SARS-CoV-2, have caused severe human epidemics in the last 16 years.
• Coronavirus disease-19 (COVID-19) presents a global health and economic challenge due to limited understanding of severe disease risk factors, diagnostics, and treatments.
• While betacoronaviruses typically elicit protective immunity, SARS-CoV-2 can trigger detrimental inflammatory responses, complicating therapeutic strategies.

Purpose of the Study:

• To review innate and cognate immune responses to pathogenic coronaviruses.
• To elucidate mechanisms underlying protective versus deleterious immune reactions against SARS-CoV, MERS-CoV, and SARS-CoV-2.
• To inform ongoing clinical trials for immunostimulatory and immunoregulatory therapeutics.

Main Methods:

• Literature review of innate and adaptive immune responses to coronaviruses.
• Analysis of mechanisms driving protective immunity versus inflammatory damage in COVID-19.
• Synthesis of current knowledge on coronavirus-induced immune responses.

Main Results:

• Coronaviruses can induce both protective and damaging immune responses.
• Dysregulated immune responses in COVID-19 can lead to severe disease and intensive care unit admission.
• Mechanisms determining the balance between protective and deleterious immunity remain incompletely understood.

Conclusions:

• A deeper understanding of immune responses is critical for combating coronavirus epidemics.
• Targeting immune mechanisms may lead to novel therapeutic strategies for severe COVID-19.
• Further research is needed to clarify the immune pathways influencing COVID-19 outcomes.