Phenotypic and functional changes of T cell subsets after CoronaVac vaccination

Phoksawat, Wisitsak, Nithichanon, Arnone, Lerdsamran, Hatairat, Wongratanacheewin, Surasakdi, Meesing, Atibordee, Pipattanaboon, Chonlatip, Kanthawong, Sakawrat, Aromseree, Sirinart, Yordpratum, Umaporn, Laohaviroj, Marut
et al (show 13 more authors) (2022) Phenotypic and functional changes of T cell subsets after CoronaVac vaccination. VACCINE, 40 (48). pp. 6963-6970.

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<h4>Background</h4>The pandemic coronavirus disease 2019 (COVID-19) is a major global public health concern and several protective vaccines, or preventive/therapeutic approaches have been developed. Sinovac-CoronaVac, an inactivated whole virus vaccine, can protect against severe COVID-19 disease and hospitalization, but less is known whether it elicits long-term T cell responses and provides prolonged protection.<h4>Methods</h4>This is a longitudinal surveillance study of SARS-CoV-2 receptor binding domain (RBD)-specific IgG levels, neutralizing antibody levels (NAb), T cell subsets and activation, and memory B cells of 335 participants who received two doses of CoronaVac. SARS-CoV-2 RBD-specific IgG levels were measured by enzyme-linked immunosorbent assay (ELISA), while NAb were measured against two strains of SARS-CoV-2, the Wuhan and Delta variants. Activated T cells and subsets were identified by flow cytometry. Memory B and T cells were evaluated by enzyme-linked immune absorbent spot (ELISpot).<h4>Findings</h4>Two doses of CoronaVac elicited serum anti-RBD antibody response, elevated B cells with NAb capacity and CD4<sup>+</sup> T cell-, but not CD8<sup>+</sup> T cell-responses. Among the CD4<sup>+</sup> T cells, CoronaVac activated mainly Th2 (CD4<sup>+</sup> T) cells. Serum antibody levels significantly declined three months after the second dose.<h4>Interpretation</h4>CoronaVac mainly activated B cells but T cells, especially Th1 cells, were poorly activated. Activated T cells were mainly Th2 biased, demonstrating development of effector B cells but not long-lasting memory plasma cells. Taken together, these results suggest that protection with CoronaVac is short-lived and that a third booster dose of vaccine may improve protection.

Item Type: Article
Uncontrolled Keywords: Antibody, CoranaVac, COVID-19, SARS-CoV-2, T cell subsets, Vaccine
Divisions: Faculty of Health and Life Sciences
Faculty of Health and Life Sciences > Institute of Infection, Veterinary and Ecological Sciences
Depositing User: Symplectic Admin
Date Deposited: 23 Jan 2023 08:40
Last Modified: 23 Jan 2023 08:42
DOI: 10.1016/j.vaccine.2022.10.017
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