• FluTrackers.com Inc. does not provide medical advice. Information on this web site is collected from various internet resources, and the FluTrackers board of directors makes no warranty to the safety, efficacy, correctness or completeness of the information posted on this site by any author or poster. The information collated here is for instructional and/or discussion purposes only and is NOT intended to diagnose or treat any disease, illness, or other medical condition. Every individual reader or poster should seek advice from their personal physician/healthcare practitioner before considering or using any interventions that are discussed on this website. By continuing to access this website you agree to consult your personal physican before using any interventions posted on this website, and you agree to hold harmless FluTrackers.com Inc., the board of directors, the members, and all authors and posters for any effects from use of any medication, supplement, vitamin or other substance, device, intervention, etc. mentioned in posts on this website, or other internet venues referenced in posts on this website.
  • We are not asking for any donations. Do not donate to any entity who says they are raising funds for us.

Sci Rep . Temporal correlations between RBD-ACE2 blocking and binding antibodies to SARS-CoV-2 variants in CoronaVac-vaccinated individuals and the

tetano

Editor, Senior Moderator
Sci Rep


. 2025 May 6;15(1):15831.
doi: 10.1038/s41598-025-98627-3. Temporal correlations between RBD-ACE2 blocking and binding antibodies to SARS-CoV-2 variants in CoronaVac-vaccinated individuals and their persistence in COVID-19 patients

Prapassorn Poolchanuan[SUP] 1 [/SUP], Wasin Matsee[SUP] 2 3 [/SUP], Adul Dulsuk[SUP] 1 [/SUP], Rungnapa Phunpang[SUP] 1 [/SUP], Chakkaphan Runcharoen[SUP] 4 5 [/SUP], Thitiya Boonprakob[SUP] 6 [/SUP], Onura Hemtong[SUP] 6 [/SUP], Suchada Chowplijit[SUP] 7 [/SUP], Vachara Chuapaknam[SUP] 7 [/SUP], Tanaya Siripoon[SUP] 2 8 [/SUP], Phimphan Pisutsan[SUP] 2 3 [/SUP], Watcharapong Piyaphanee[SUP] 2 3 [/SUP], Wathusiri Khongsiri[SUP] 1 [/SUP], Nathamon Kosoltanapiwat[SUP] 1 [/SUP], Le Van Tan[SUP] 9 10 [/SUP], Susanna Dunachie[SUP] 11 12 [/SUP], Chee Wah Tan[SUP] 13 14 [/SUP], Lin-Fa Wang[SUP] 13 [/SUP], Wasun Chantratita[SUP] 4 [/SUP], Viravarn Luvira[SUP] 2 8 [/SUP], Narisara Chantratita[SUP] 15 16 [/SUP]; SEACOVARIANTS



Collaborators, Affiliations
Abstract

Antibodies play a crucial role in protection against SARS-CoV-2. Understanding the correlation between binding and functional antibodies is essential to determine whether binding antibody levels can reliably predict neutralizing activity. We assessed antibody responses in 111 individuals vaccinated with the inactivated vaccine CoronaVac and 111 COVID-19 patients in Thailand. Plasma levels of ACE2-blocking antibodies targeting the receptor-binding domain (RBD) of SARS-Co-V2 variants were measured before vaccination and at 14 and 28 days after the second dose using a multiplex surrogate virus neutralization test. Anti-spike and anti-nucleocapsid antibodies were quantified by electrochemiluminescence immunoassay, and anti-RBD IgG by ELISA. After vaccination, blocking, anti-spike, and IgG antibody levels increased but declined rapidly within a month, whereas antibody levels in COVID-19 patients increased and persisted. Blocking and anti-spike antibody correlated at day 14 post-vaccination but not at day 28. In COVID-19 patients, correlations were moderate at day 14, and stronger at day 28. Correlations were weaker for Omicron subvariants than for the ancestral strain and non-Omicron variants. The weak correlation between blocking and anti-RBD IgG suggests binding antibodies might not predict neutralizing activity. These findings highlight the temporal nature of CoronaVac-induced immunity and the need for booster doses and variant-adapted vaccine.

Keywords: Anti-spike antibody; COVID-19; Correlation; RBD-ACE2 blocking antibody; SARS-CoV-2; Vaccine.

 
Back
Top Bottom