Receptor binding domain‐IgG levels correlate with protection in residents facing SARS‐CoV‐2 B.1.1.7 outbreaks

Abstract

Background Limited information exists on nursing home (NH) residents regarding BNT162b2 vaccine efficacy in preventing SARS‐CoV‐2 and severe COVID‐19, and its association with post‐vaccine humoral response. Methods 396 residents from seven NHs suffering a SARS‐CoV‐2 B.1.1.7 (VOC‐α) outbreak at least 14 days after a vaccine campaign were repeatedly tested using SARS‐CoV‐2 real‐time reverse‐transcriptase polymerase chain reaction on nasopharyngeal swab test (RT‐qPCR). SARS‐CoV‐2 receptor‐binding domain (RBD) of the S1 subunit (RBD‐IgG) was measured in all residents. Nucleocapsid antigenemia (N‐Ag) was measured in RT‐qPCR‐positive residents and serum neutralizing antibodies in vaccinated residents from one NH. Results The incidence of positive RT‐qPCR was lower in residents vaccinated by two doses (72/317; 22.7%) vs one dose (10/31; 32.3%) or non‐vaccinated residents (21/48; 43.7%; p < .01). COVID‐19–induced deaths were observed in 5 of the 48 non‐vaccinated residents (10.4%), in 2 of the 31 who had received one dose (6.4%), and in 3 of the 317 (0.9%) who had received two doses ( p = .0007). Severe symptoms were more common in infected non‐vaccinated residents (10/21; 47.6%) than in infected vaccinated residents (15/72; 21.0%; p = .002). Higher levels of RBD‐IgG ( n = 325) were associated with a lower SARS‐CoV‐2 incidence. No in vitro serum neutralization activity was found for RBD‐IgG levels below 1050 AU/ml. RBD‐IgG levels were inversely associated with N‐Ag levels, found as a risk factor of severe COVID‐19. Conclusions Two BNT162b2 doses are associated with a 48% reduction of SARS‐CoV‐2 incidence and a 91.3% reduction of death risk in residents from NHs facing a VOC‐α outbreak. Post‐vaccine RBD‐IgG levels correlate with BNT162b2 protection against SARS‐CoV‐2 B.1.1.7.

Omicron: A SARS‐CoV‐2 variant of real concern

“…Among other examples, gaseous and particulate matter (PM) concentrations diminished during the 2020 spring lockdown in forty-four cities in northern China due to reduced human activity and travel restrictions. 4 However, during the same period in the UK, after an initial abrupt reduction, nitrogen dioxide (NO 2 ) increased gradually, suggesting that the early return of vehicles to the road during the lockdown had already offset much of the temporary air-quality improvement. 5 Regarding health impact, the risk of COVID-19 mortality during lockdown diminished alongside major air pollutants in Delhi, India, 6 but not in Mexico City, Mexico, where an inverse relationship was found in the case of fine particulate matter.…”

“…Antibodies directed to RBD are critically important for virus‐neutralization because the RBD‐ACE2 interaction represents the port of entry for the virus into cells leading to its replication in the host and to the consecutive spreading in the population. 3 , 4 The ability of RBD‐specific antibodies to prevent RBD binding to ACE2 can be measured with surrogate molecular interaction assays, 5 which mimic classical virus‐neutralization tests 3 and can therefore be quickly adapted to newly emerging SARS‐CoV‐2 variants of concern by using RBDs from the corresponding virus variants.…”

“…Antibodies directed to RBD are critically important for virus-neutralization because the RBD-ACE2 interaction represents the port of entry for the virus into cells leading to its replication in the host and to the consecutive spreading in the population. 3,4 The ability of RBD-specific antibodies to prevent RBD binding to ACE2 can be measured with surrogate molecular interaction assays, 5 which mimic classical virus-neutralization tests 3 and can therefore be quickly adapted to newly emerging SARS-CoV-2 variants of concern by using RBDs from the corresponding virus variants.Here, we compared the IgG recognition of RBD from the original Wuhan strain and recent variants of concern Delta (Pango B.1.617.2) and Omicron (Pango B.1.1.529) (Table S1) using sera from a random sample of adult COVID-19 convalescent patients (Table S2: C1-C20)This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.…”

Vaccine based on folded receptor binding domain‐PreS fusion protein with potential to induce sterilizing immunity to SARS‐CoV‐2 variants

“…Antibodies directed against RBD are important for virus neutralization, 23,24 correlate with protection in vaccinated subjects 25 and due to their ability to prevent the virus from entering the human cell and replicating in the host could be a key for obtaining sterilizing immunity 26 . However, it was found that approximately 20% of COVID‐19 convalescent patients, although producing antibodies to other SARS‐CoV‐2 antigens and epitopes, do not sufficiently produce RBD‐specific IgG antibodies to block the RBD‐ACE2 binding and hence are poor‐ or non‐responders to RBD 23,24 …”

Interdependencies of cellular and humoral immune responses in heterologous and homologous SARS‐CoV‐2 vaccination

“…[13][14][15][16][17] Overall, levels of anti-spike-RBD (receptor-binding domain)-IgG and neutralizing antibodies (which correlate strongly) appear to be good measures of vaccine efficacy. [18][19][20][21] Recent publications report a vaccine efficiency of 80% against infections with the Alpha variant (B.1.1.7), with anti-spike-RBD-IgG titers of 506 BAU/ml or 90% efficacy for titers above 775 BAU/ml. 20,22 Similar studies for the Delta (B.1.617.2) or Omicron (B.…”