Antibody response dynamics to CoronaVac vaccine and booster immunization in adults and the elderly: A long-term, longitudinal prospective study.
IJID Reg
; 7: 222-229, 2023 Jun.
Article
in En
| MEDLINE
| ID: mdl-37102137
ABSTRACT
Background:
The long-term humoral immune response after vaccination varies between vaccines and is dependent on the accuracy of the antibody test. A better understanding of the vaccine immune response may help to define vaccination strategies against coronavirus disease 2019 (COVID-19).Objective:
To investigate the long-term immunological response to CoronaVac vaccine and determinants of breakthrough COVID-19 infection.Methods:
A long-term, prospective cohort study involving vaccinated adult and elderly subjects was conducted to investigate the presence of anti-RBD-specific immunoglobulin (Ig)G, anti-nucleocapsid IgG and anti-spike trimeric protein IgG. Antibody level dynamics and risk factors associated with breakthrough COVID-19 infection were investigated.Results:
In total, 3902 participants were included in this study. Vaccination with two doses of CoronaVac and a booster dose increased the levels of anti-RBD-specific IgG, anti-nucleocapsid IgG and anti-spike trimeric IgG significantly. In adults, anti-nucleocapsid IgG and anti-spike trimeric IgG levels decreased significantly 7 months after the second dose. In adults and the elderly, the levels of anti-spike trimeric IgG and anti-RBD IgG decreased significantly 4 and 6 months after the booster dose, respectively. Previous exposure to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and anti-spike trimeric IgG titres was independently associated with a lower probability of post-vaccination infection.Conclusions:
A significant increase in antibody levels was found after two doses of CoronaVac and a booster dose. Antibody titres declined significantly 7 months post-vaccination in participants who did not receive a booster dose. Higher levels of antibodies and previous SARS-CoV-2 infection were associated with protection against breakthrough COVID-19.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Type of study:
Observational_studies
/
Risk_factors_studies
Language:
En
Journal:
IJID Reg
Year:
2023
Document type:
Article
Affiliation country:
Brasil