Phenotypic and functional changes of T cell subsets after CoronaVac vaccination.
Vaccine
; 40(48): 6963-6970, 2022 Nov 15.
Article
in English
| MEDLINE | ID: covidwho-2082524
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
Full text:
Available
Collection:
International databases
Database:
MEDLINE
Main subject:
Viral Vaccines
/
COVID-19
Type of study:
Experimental Studies
/
Prognostic study
Topics:
Vaccines
/
Variants
Limits:
Humans
Language:
English
Journal:
Vaccine
Year:
2022
Document Type:
Article
Affiliation country:
J.vaccine.2022.10.017
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