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Review
. 2021 Dec;21(12):762-768.
doi: 10.1038/s41577-021-00631-x. Epub 2021 Oct 19.

The immunology of asymptomatic SARS-CoV-2 infection: what are the key questions?

Rosemary J Boyton  1   2 , Daniel M Altmann  3
Affiliations
Review

The immunology of asymptomatic SARS-CoV-2 infection: what are the key questions?

Rosemary J Boyton et al. Nat Rev Immunol. 2021 Dec.

Abstract

An important challenge during the COVID-19 pandemic has been to understand asymptomatic disease and the extent to which this may be a source of transmission. As asymptomatic disease is by definition hard to screen for, there is a lack of clarity about this aspect of the COVID-19 spectrum. Studies have considered whether the prevalence of asymptomatic disease is determined by differences in age, demographics, viral load, duration of shedding, and magnitude or durability of immunity. It is clear that adaptive immunity is strongly activated during asymptomatic infection, but some features of the T cell and antibody response may differ from those in symptomatic disease. Areas that need greater clarity include the extent to which asymptomatic disease leads to persistent symptoms (long COVID), and the quality, quantity and durability of immune priming required to confer subsequent protection.

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Conflict of interest statement

R.J.B. and D.M.A. are members of the Global T cell Expert Consortium and have consulted for Oxford Immunotec outside the submitted work.

Figures

Fig. 1
Fig. 1. Immune responses across the spectrum of COVID-19 from asymptomatic to severe disease.
Ab, antibody; IP10, IFNγ-induced protein 10; NK, natural killer.
See this image and copyright information in PMC

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