Neutralizing antibodies and cellular immune response after two doses of inactivated SARS-CoV-2 vaccine in China.
Expert Rev Vaccines
; 21(10): 1465-1473, 2022 10.
Article
in English
| MEDLINE | ID: covidwho-1937581
ABSTRACT
BACKGROUND:
As of 2022, inactivated SARS-CoV-2 vaccines had been used in more than 91 countries. However, limited real world information was available on the immune responses of the inactivated SARS-CoV-2 vaccine.METHODS:
We used SARS-CoV-2 pseudovirues to determine the neutralizing antibodies (NAbs) to wild type and several global variants and utilized enzyme-linked immunosorbent assay to investigate IFN-γ-secreting T-cell responses to SARS-CoV-2 among 240 vaccinated individuals after two doses of inactivated vaccine in China.RESULTS:
A majority of the vaccinated (>90%) developed robust NAbs and T-cell responses to SARS-CoV-2 in the first two months after the second dose. After six months, only 37.0% and 44.0% of vaccinees had NAbs and T-cell immunity to SARS-CoV-2, respectively. Immune serum retained most of its neutralizing potency against the Alpha and Iota variants, but lost significant neutralizing potency against the Beta, Kappa, Delta, and Omicron variants. Only 40% of vaccine-sera retained low-level neutralization activities to Omicron, with a 14.7-fold decrease compared to the wild type.CONCLUSION:
The inactivated SARS-CoV-2 vaccine stimulated robust NAbs and T-cell immune responses in the first two months after the second dose but the immune effect dropped rapidly, highlighing that a third dose or additional booster immunizations may be required to boost immunity against SARS-CoV-2.Keywords
Full text:
Available
Collection:
International databases
Database:
MEDLINE
Main subject:
Viral Vaccines
/
COVID-19
Topics:
Vaccines
/
Variants
Limits:
Humans
Language:
English
Journal:
Expert Rev Vaccines
Journal subject:
Allergy and Immunology
Year:
2022
Document Type:
Article
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