Functional SARS-CoV-2-specific immune memory persists after mild COVID-19.

Area of Science:

• Immunology
• Virology
• Infectious Diseases

Background:

• The global SARS-CoV-2 pandemic necessitates understanding immune responses to mild infections.
• It remains unclear if mild coronavirus disease 2019 (COVID-19) induces durable immunological memory crucial for herd immunity.

Approach:

• This study longitudinally assessed immune memory in individuals recovered from mild COVID-19.
• Investigated the development and persistence of SARS-CoV-2-specific antibodies and memory lymphocytes (B and T cells).

Key Points:

• Recovered individuals exhibited sustained SARS-CoV-2-specific IgG antibodies and neutralizing plasma.
• Virus-specific memory B and T cells were detected and persisted for over three months post-symptom onset.
• Memory lymphocytes displayed functional characteristics of potent antiviral immunity, including IFN-γ secretion and antigen-specific expansion.

Conclusions:

• Mild COVID-19 elicits a robust and persistent immunological memory.
• The findings demonstrate that memory lymphocytes generated by mild SARS-CoV-2 infection possess functional attributes associated with protective antiviral immunity.