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

Area of Science:

• Immunology
• Virology
• Epidemiology

Background:

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

Approach:

• A longitudinal study assessed immune memory in individuals recovered from mild COVID-19.
• Investigated the development and persistence of SARS-CoV-2-specific antibodies and memory lymphocytes.

Key Points:

• Recovered individuals exhibited sustained SARS-CoV-2-specific IgG antibodies and neutralizing plasma.
• Virus-specific memory B and T cells persisted for over three months post-symptom onset, with some increasing numerically.
• Memory T cells secreted IFN-γ and expanded upon re-encounter, while memory B cells produced neutralizing antibodies.

Conclusions:

• Mild COVID-19 infection elicits a robust and persistent immunological memory.
• The generated memory lymphocytes display functional characteristics indicative of potent antiviral protective immunity.