Waning anti-SARS-CoV-2 receptor-binding domain total antibody in CoronaVac-vaccinated individuals in Indonesia.

Content Provider	Europe PMC
Author	Harapan, Harapan Ar Royan, Hibban Tyas, Islam Ing Nadira, Auda Abdi, Irham Faraby Anwar, Samsul Husnah, Milda Ichsan, Ichsan Pranata, Agung Mudatsir, Mudatsir Syukri, Maimun Rizal, Samsul ., Razali ., Hamdani Kurniawan, Rudi Irwansyah, Irwansyah Sofyan, Sarwo Edhy
Copyright Year	2023
Abstract	Background: The decrease of immunity acquired from COVID-19 vaccines is a potential cause of breakthrough infection. Understanding the dynamics of immune responses of vaccine-induced antibodies post-vaccination is important. This study aimed to measure the level of anti-SARS-CoV-2 receptor-binding domain (RBD) total antibody in individuals at different time points upon the receipt of the second dose of CoronaVac vaccine, as well as evaluate the plausible associated factors.Methods: A cross-sectional study was conducted among CoronaVac-vaccinated residents in Banda Aceh, Indonesia. The level of anti-SARS-CoV-2 RBD total antibody was measured using Elecsys immunoassay. A set of standardized and validated questionnaires were used to assess the demographics and other associated factors.Results: Our results showed waning anti-SARS-CoV-2 RBD total antibody titres over time post-vaccination. Compared to samples of the first month post-vaccination, the antibody titres were significantly lower than those of five-months (mean 184.6 vs. 101.8 U/mL, p = 0.009) and six-months post-vaccination (mean 184.6 vs. 95.59 U/mL, p = 0.001). This suggests that the length of time post-vaccination was negatively correlated with titre of antibody. A protective level of antibody titres (threshold of 15 U/mL) was observed from all the samples vaccinated within one to three months; however, only 73.7% and 78.9% of the sera from five- and six-months possessed the protective titres, respectively. The titre of antibody was found significantly higher in sera of individuals having a regular healthy meal intake compared to those who did not (mean 136.7 vs. 110.4 U/mL, p = 0.044), including in subgroup analysis that included those five to six months post-vaccination only (mean 79.0 vs. 134.5 U/mL, p = 0.009).Conclusions: This study provides insights on the efficacy of CoronaVac vaccine in protecting individuals against SARS-CoV-2 infection over time, which may contribute to future vaccination policy management to improve and prolong protective strategy.
Volume Number	11
PubMed Central reference number	PMC10209622
PubMed reference number	37260419
Journal	F1000Research [F1000Res]
e-ISSN	20461402
DOI	10.12688/f1000research.109676.2
Language	English
Publisher	F1000 Research Limited
Publisher Date	2022-01-01
Publisher Place	London, UK
Access Restriction	Open
Rights License	This is an open access article distributed under the terms of the Creative Commons Attribution Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Copyright: © 2023 Harapan H et al.
Subject Keyword	COVID-19 neutralizing antibody CoronaVac anti-SRBD Sinovac
Content Type	Text
Resource Type	Article
Subject	Immunology and Microbiology Pharmacology, Toxicology and Pharmaceutics Medicine Biochemistry, Genetics and Molecular Biology