Repeated Exposure to Subinfectious Doses of SARS-CoV-2 May Promote T Cell Immunity and Protection against Severe COVID-19

De Angelis, Maria Laura; Francescangeli, Federica; Rossi, Rachele; Giuliani, Alessandro; De Maria, Ruggero; Zeuner, Ann

doi:10.3390/v13060961

Submit to this Journal Review for this Journal Edit a Special Issue

Article Menu

...

Open AccessOpinion

Repeated Exposure to Subinfectious Doses of SARS-CoV-2 May Promote T Cell Immunity and Protection against Severe COVID-19

Maria Laura De Angelis

^1,†,

Federica Francescangeli

^1,†

¹,

^3,4,‡ and

^1,*,‡

Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità (National Institute of Health), 00161 Rome, Italy

Environment and Health Department, Istituto Superiore di Sanità, 00161 Rome, Italy

Department of Medicine and Translational Surgery, Università Cattolica del Sacro Cuore, 00168 Rome, Italy

⁴

Institute of General Pathology, Policlinico Universitario Fondazione A. Gemelli, 00168 Rome, Italy

Author to whom correspondence should be addressed.

^†

The first two authors contributed equally to the manuscript.

^‡

The last two authors contributed equally to the manuscript.

Academic Editors: Luis Martinez-Sobrido and Fernando Almazan Toral

Viruses 2021, 13(6), 961; https://doi.org/10.3390/v13060961

Received: 2 April 2021 / Revised: 14 May 2021 / Accepted: 19 May 2021 / Published: 22 May 2021

(This article belongs to the Collection SARS-CoV-2 and COVID-19)

View Full-Text Download PDF

Browse Figures

Review Reports Citation Export

Abstract

Europe is experiencing a third wave of COVID-19 due to the spread of highly transmissible SARS-CoV-2 variants. A number of positive and negative factors constantly shape the rates of COVID-19 infections, hospitalization, and mortality. Among these factors, the rise in increasingly transmissible variants on one side and the effect of vaccinations on the other side create a picture deeply different from that of the first pandemic wave. Starting from the observation that in several European countries the number of COVID-19 infections in the second and third pandemic wave increased without a proportional rise in disease severity and mortality, we hypothesize the existence of an additional factor influencing SARS-CoV-2 dynamics. This factor consists of an immune defence against severe COVID-19, provided by SARS-CoV-2-specific T cells progressively developing upon natural exposure to low virus doses present in populated environments. As suggested by recent studies, low-dose viral particles entering the respiratory and intestinal tracts may be able to induce T cell memory in the absence of inflammation, potentially resulting in different degrees of immunization. In this scenario, non-pharmaceutical interventions would play a double role, one in the short term by reducing the detrimental spreading of SARS-CoV-2 particles, and one in the long term by allowing the development of a widespread (although heterogeneous and uncontrollable) form of immune protection. View Full-Text

Keywords: COVID-19; SARS-CoV-2; protective immunity; T cell responses; facial masking; fomites; environmental exposure; memory T cells

▼ Show Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

Share and Cite

MDPI and ACS Style

De Angelis, M.L.; Francescangeli, F.; Rossi, R.; Giuliani, A.; De Maria, R.; Zeuner, A. Repeated Exposure to Subinfectious Doses of SARS-CoV-2 May Promote T Cell Immunity and Protection against Severe COVID-19. Viruses 2021, 13, 961. https://doi.org/10.3390/v13060961

AMA Style

De Angelis ML, Francescangeli F, Rossi R, Giuliani A, De Maria R, Zeuner A. Repeated Exposure to Subinfectious Doses of SARS-CoV-2 May Promote T Cell Immunity and Protection against Severe COVID-19. Viruses. 2021; 13(6):961. https://doi.org/10.3390/v13060961

Chicago/Turabian Style

De Angelis, Maria L., Federica Francescangeli, Rachele Rossi, Alessandro Giuliani, Ruggero De Maria, and Ann Zeuner. 2021. "Repeated Exposure to Subinfectious Doses of SARS-CoV-2 May Promote T Cell Immunity and Protection against Severe COVID-19" Viruses 13, no. 6: 961. https://doi.org/10.3390/v13060961

Find Other Styles

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Metrics

Abstract views Pdf views Html views

Article Menu

Repeated Exposure to Subinfectious Doses of SARS-CoV-2 May Promote T Cell Immunity and Protection against Severe COVID-19

Abstract

Share and Cite

Article Metrics

Article Access Statistics

Article Access Map by Country/Region

Further Information

Guidelines

MDPI Initiatives

Follow MDPI