Long-Term Humoral Immune Response against SARS-CoV-2 after Natural Infection and Subsequent Vaccination According to WHO International Binding Antibody Units (BAU/mL).
Viruses
; 13(12)2021 11 23.
Article
in English
| MEDLINE | ID: covidwho-1542791
ABSTRACT
The new WHO reference standard allows for the definition of serum antibodies against various SARS-CoV-2 antigens in terms of binding antibody units (BAU/mL) and thus to compare the results of different ELISA systems. In this study, the concentration of antibodies (ABs) against both the S- and the N-protein of SARS-CoV-2 as well as serum neutralization activity were evaluated in three patients after a mild course of COVID-19. Serum samples were collected frequently during a period of over one year. Furthermore, in two individuals, the effects of an additional vaccination with a mRNA vaccine containing the S1-RBD sequence on these antibodies were examined. After natural infection, the antibodies (IgA, IgG) against the S1-protein remained elevated above the established cut-off to positivity (S-IgA 60 BAU/mL and S-IgG 50 BAU/mL, respectively) for over a year in all patients, while this was not the case for ABs against the N-protein (cut-off N-IgG 40 BAU/mL, N-IgA 256 BAU/mL). Sera from all patients retained the ability to neutralize SARS-CoV-2 for more than a year. Vaccination resulted in a rapid boost of antibodies to S1-protein but, as expected, not to the N-protein. Most likely, the wide use of the WHO reference preparation will be very useful in determining the individual immune status of patients after an infection with SARS-CoV-2 or after vaccination.
Keywords
Full text:
Available
Collection:
International databases
Database:
MEDLINE
Main subject:
COVID-19 Serological Testing
/
SARS-CoV-2
/
COVID-19
/
Antibodies, Viral
Type of study:
Diagnostic study
/
Experimental Studies
/
Prognostic study
Topics:
Long Covid
/
Vaccines
Limits:
Adult
/
Female
/
Humans
/
Male
/
Middle aged
Language:
English
Year:
2021
Document Type:
Article
Affiliation country:
V13122336
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