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

Abstract

To the Editor, As of today (February 14, 2022), more than 410 million persons (https://coron avirus.jhu.edu/map.html) have reportedly been infected by SARS-CoV-2. Furthermore, mass production and global application of COVID-19 vaccines have begun (Supplemental reference S3). Both factors certainly contribute to the fact, that although numbers of worldwide SARS-CoV-2 infections end of 2021 were more than double as high as in the end of 2020, the number of COVID-19-associated deaths has dropped to approximately 50% at the same time (https://coron avirus.jhu.edu/map.html). However, the immunity to SARS-CoV-2 which has been established so far is challenged by the appearance of SARS-CoV-2-variants which may escape cellular (Supplemental reference S4) and antibody-dependent immunity (Supplemental reference S5). The recently described variant of concern (VOC) Omicron, which has emerged in South Africa in November 2021, is spreading in the meantime rapidly all over the world and has become a matter of great concern because it shows more changes in the SARS-CoV-2 genome that may affect immunity as compared with earlier variants 1 (Supplemental references S6-S9).In particular, Omicron has significantly more amino acid mutations in the SARS-CoV-2 receptor-binding domain (RBD), which binds to the ACE2 receptor on human cells, as compared with previous SARS-CoV-2 variants 2 (Table S1). 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.

Vaccination with a bacterial peptide conjugated to SARS-CoV-2 receptor-binding domain accelerates immunity and protects against COVID-19

“…Interestingly, we observed iScience Article reactivity against the RBM-Omicron, although it was lower compared to the reactivity against the RBM with the original sequence (RBM-wild type) and RBM-Delta (Figure 2I). This finding is in line with other studies, which show a reduced reactivity of serum antibodies from convalescent and vaccinated individuals against Omicron, but not against the Delta variant (Gattinger et al, 2022;Rossler et al, 2022).…”

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

“…The RBD-specific IgG antibodies induced in the human subject with PreS-RBD cross-reacted with RBD mutants and variants including even the highly mutated VOC omicron (Figure 4B, Figures S1-S3) [17][18][19][20] suggesting that the PreS-RBD-based vaccine has the potential to cross-protect even against strongly mutated VOCs.…”

“…The RBD‐specific IgG antibodies induced in the human subject with PreS‐RBD cross‐reacted with RBD mutants and variants including even the highly mutated VOC omicron (Figure 4B , Figures S1–S3 ) 17 , 18 , 19 , 20 suggesting that the PreS‐RBD‐based vaccine has the potential to cross‐protect even against strongly mutated VOCs. PreS‐RBD contains two RBD domains, one fused to the N‐ and one fused to the C‐terminus of PreS, and it is therefore be quite easy to enhance the cross‐protective effect by including RBDs from the two most divergent and most common SARS‐CoV‐2 VOCs in the PreS‐RBD construct.…”

“… 17 Indeed, omicron was detected in Asia in mid‐November 18 and has since become a dominant VOC in all parts of the world. 17 First reports already indicate that currently available COVID‐19 vaccines may confer less protection against omicron 19 , 20 , 21 , 22 infection.…”

Lack of Induction of RBD-Specific Neutralizing Antibodies despite Repeated Heterologous SARS-CoV-2 Vaccination Leading to Seroconversion and Establishment of T Cell-Specific Memory in a Patient in Remission of Multiple Myeloma

“…In healthy individuals, SARS-CoV-2 genetic vaccines are generally very successful, inducing high levels of spike protein (S)-specific antibodies in parallel with SARS-CoV-2-specific T-cell memory [ 1 , 2 , 3 , 4 , 5 ]. The induced immunity subsequently protects against severe COVID-19, but booster vaccinations must be given in a timely manner to counteract the consistent decline in antibody levels 4–6 months after completion of the 2-shot immunization cycle and to increase the likelihood of protection against new mutant strains of SARS-CoV-2 [ 6 ]. However, the situation is getting more complicated in individuals who have had to undergo B-cell-depleting therapy, e.g., after non-Hodgkin lymphoma, and are thus potentially immunocompromised [ 7 , 8 , 9 ].…”