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Vaccine
. 2022 Oct 22;S0264-410X(22)01265-8.
doi: 10.1016/j.vaccine.2022.10.017. Online ahead of print.
Phenotypic and functional changes of T cell subsets after CoronaVac vaccination
Wisitsak Phoksawat 1 , Arnone Nithichanon 1 , Hatairat Lerdsamran 2 , Surasakdi Wongratanacheewin 3 , Atibordee Meesing 4 , Chonlatip Pipattanaboon 5 , Sakawrat Kanthawong 6 , Sirinart Aromseree 7 , Umaporn Yordpratum 8 , Marut Laohaviroj 9 , Viraphong Lulitanond 3 , Sorujsiri Chareonsudjai 1 , Pilaipan Puthavathana 2 , Ludthawun Kamuthachad 10 , Chatcharin Kamsom 10 , Chakrit Thapphan 10 , Kanin Salao 1 , Arunya Chonlapan 11 , Punnapat Nawawishkarun 11 , Jarunee Prasertsopon 2 , Hans J Overgaard 12 , Steven W Edwards 13 , Supranee Phanthanawiboon 14
Affiliations
- PMID: 36283898
- DOI: 10.1016/j.vaccine.2022.10.017
Abstract
Background: 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.
Methods: 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).
Findings: Two doses of CoronaVac elicited serum anti-RBD antibody response, elevated B cells with NAb capacity and CD4+ T cell-, but not CD8+ T cell-responses. Among the CD4+ T cells, CoronaVac activated mainly Th2 (CD4+ T) cells. Serum antibody levels significantly declined three months after the second dose.
Interpretation: 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.
Keywords: Antibody; COVID-19; CoranaVac; SARS-CoV-2; T cell subsets; Vaccine.