Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2)–Specific T Cells and Antibodies in Coronavirus Disease 2019 (COVID-19) Protection: A Prospective Study
Authors: Molodtsov Ivan A , Kegeles Evgenii , Mitin Alexander N , Mityaeva Olga , Musatova Oksana E , Panova Anna E , Pashenkov Mikhail V , Peshkova Iuliia O , Alsalloum Almaqdad , Asaad Walaa , Budikhina Anna S , Deryabin Alexander S , Dolzhikova Inna V , Filimonova Ioanna N , Gracheva Alexandra N , Ivanova Oxana I , Kizilova Anastasia , Komogorova Viktoria V , Komova Anastasia , Kompantseva Natalia I , Kucheryavykh Ekaterina , Lagutkin Denis А , Lomakin Yakov A , Maleeva Alexandra V , Maryukhnich Elena V , Mohammad Afraa , Murugin Vladimir V , Murugina Nina E , Navoikova Anna , Nikonova Margarita F , Ovchinnikova Leyla A , Panarina Yana , Pinegina Natalia V , Potashnikova Daria M , Romanova Elizaveta V , Saidova Aleena A , Sakr Nawar , Samoilova Anastasia G , Serdyuk Yana , Shakirova Naina T , Sharova Nina I , Sheetikov Saveliy A , Shemetova Anastasia F , Shevkova Liudmila V , Shpektor Alexander V , Trufanova Anna , Tvorogova Anna V , Ukrainskaya Valeria M , Vinokurov Anatoliy S , Vorobyeva Daria A , Zornikova Ksenia V , Efimov Grigory A , Khaitov Musa R , Kofiadi Ilya A , Komissarov Alexey A , Logunov Denis Y , Naigovzina Nelli B , Rubtsov Yury P , Vasilyeva Irina A , Volchkov Pavel , Vasilieva Elena 
Published: April 2022

Background

During the ongoing coronavirus disease 2019 (COVID-19) pandemic, many individuals were infected with and have cleared the virus, developing virus-specific antibodies and effector/memory T cells. An important unanswered question is what levels of T-cell and antibody responses are sufficient to protect from the infection.

Methods

In 5340 Moscow residents, we evaluated anti–severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunoglobulin M (IgM)/immunoglobulin G (IgG) titers and frequencies of the T cells specific to the membrane, nucleocapsid, and spike proteins of SARS-CoV-2, using interferon gamma (IFN-γ) enzyme-linked immunosorbent spot (ELISpot) assay. Additionally, we evaluated the fractions of virus-specific CD4+ and CD8+ T cells using intracellular staining of IFN-γ and interleukin 2 followed by flow cytometry. We analyzed the COVID-19 rates as a function of the assessed antibody and T-cell responses, using the Kaplan–Meier estimator method, for up to 300 days postinclusion.

Results

We showed that T-cell and antibody responses are closely interconnected and are commonly induced concurrently. Magnitudes of both responses inversely correlated with infection probability. Individuals positive for both responses demonstrated the highest levels of protectivity against the SARS-CoV-2 infection. A comparable level of protection was found in individuals with antibody response only, whereas the T-cell response by itself granted only intermediate protection.

Conclusions

We found that the contribution of the virus-specific antibodies to protection against SARS-CoV-2 infection is more pronounced than that of the T cells. The data on the virus-specific IgG titers may be instructive for making decisions in personalized healthcare and public anti–COVID-19 policies.

Clinical Trials Registration. NCT04898140.