Project description:SARS-CoV-2 Omicron subvariants BA.2.12.1 and BA.4/5 have surged notably to become dominant in the United States and South Africa, respectively1,2. These new subvariants carrying further mutations in their spike proteins raise concerns that they may further evade neutralizing antibodies, thereby further compromising the efficacy of COVID-19 vaccines and therapeutic monoclonals. We now report findings from a systematic antigenic analysis of these surging Omicron subvariants. BA.2.12.1 is only modestly (1.8-fold) more resistant to sera from vaccinated and boosted individuals than BA.2. However, BA.4/5 is substantially (4.2-fold) more resistant and thus more likely to lead to vaccine breakthrough infections. Mutation at spike residue L452 found in both BA.2.12.1 and BA.4/5 facilitates escape from some antibodies directed to the so-called class 2 and 3 regions of the receptor-binding domain3. The F486V mutation found in BA.4/5 facilitates escape from certain class 1 and 2 antibodies but compromises the spike affinity for the viral receptor. The R493Q reversion mutation, however, restores receptor affinity and consequently the fitness of BA.4/5. Among therapeutic antibodies authorized for clinical use, only bebtelovimab retains full potency against both BA.2.12.1 and BA.4/5. The Omicron lineage of SARS-CoV-2 continues to evolve, successively yielding subvariants that are not only more transmissible but also more evasive to antibodies.

| S-EPMC9385487 | biostudies-literature

Impact of mutations defining SARS-CoV-2 Omicron subvariants BA.2.12.1 and BA.4/5 on Spike function and neutralization.

Project description:Additional mutations in the viral Spike protein helped the BA.2.12.1 and BA.4/5 SARS-CoV-2 Omicron subvariants to outcompete the parental BA.2 subvariant. Here, we determined the functional impact of mutations that newly emerged in the BA.2.12.1 (L452Q, S704L) and BA.4/5 (Δ69-70, L452R, F486V, R493Q) Spike proteins. Our results show that mutation of L452Q/R or F486V typically increases and R493Q or S704L impair BA.2 Spike-mediated infection. In combination, changes of Δ69-70, L452R, and F486V contribute to the higher infectiousness and fusogenicity of the BA.4/5 Spike. L452R/Q and F486V in Spike are mainly responsible for reduced sensitivity to neutralizing antibodies. However, the combined mutations are required for full infectivity, reduced TMPRSS2 dependency, and immune escape of BA.4/5 Spike. Thus, it is the specific combination of mutations in BA.4/5 Spike that allows increased functionality and immune evasion, which helps to explain the temporary dominance and increased pathogenicity of these Omicron subvariants.

| S-EPMC10661123 | biostudies-literature

Effectiveness of mRNA-1273 vaccination against SARS-CoV-2 omicron subvariants BA.1, BA.2, BA.2.12.1, BA.4, and BA.5.

Project description:Studies have reported reduced natural SARS-CoV-2 infection- and vaccine-induced neutralization against omicron BA.4/BA.5 compared with earlier omicron subvariants. This test-negative case-control study evaluates mRNA-1273 vaccine effectiveness (VE) against infection and hospitalization with omicron subvariants. The study includes 30,809 SARS-CoV-2 positive and 92,427 SARS-CoV-2 negative individuals aged ≥18 years tested during 1/1/2022-6/30/2022. While 3-dose VE against BA.1 infection is high and wanes slowly, VE against BA.2, BA.2.12.1, BA.4, and BA.5 infection is initially moderate to high (61.0%-90.6% 14-30 days post third dose) and wanes rapidly. The 4-dose VE against infection with BA.2, BA.2.12.1, and BA.4 ranges between 64.3%-75.7%, and is low (30.8%) against BA.5 14-30 days post fourth dose, disappearing beyond 90 days for all subvariants. The 3-dose VE against hospitalization for BA.1, BA.2, and BA.4/BA.5 is 97.5%, 82.0%, and 72.4%, respectively; 4-dose VE against hospitalization for BA.4/BA.5 is 88.5%. Evaluation of the updated bivalent booster is warranted.

| S-EPMC9836332 | biostudies-literature

mouse ACE2 receptor bound to SARS-CoV-2 variant Omicron BA.2.12.1 Spike

Project description: Not available

| EMPIAR-11180 | biostudies-other

Augmented neutralisation resistance of emerging omicron subvariants BA.2.12.1, BA.4, and BA.5.

Project description: Not available

| S-EPMC9239574 | biostudies-literature

Determinants of Spike infectivity, processing, and neutralization in SARS-CoV-2 Omicron subvariants BA.1 and BA.2.

Project description:SARS-CoV-2 Omicron rapidly outcompeted other variants and currently dominates the COVID-19 pandemic. Its enhanced transmission and immune evasion are thought to be driven by numerous mutations in the Omicron Spike protein. Here, we systematically introduced BA.1 and/or BA.2 Omicron Spike mutations into the ancestral Spike protein and examined the impacts on Spike function, processing, and susceptibility to neutralization. Individual mutations of S371F/L, S375F, and T376A in the ACE2-receptor-binding domain as well as Q954H and N969K in the hinge region 1 impaired infectivity, while changes to G339D, D614G, N764K, and L981F moderately enhanced it. Most mutations in the N-terminal region and receptor-binding domain reduced the sensitivity of the Spike protein to neutralization by sera from individuals vaccinated with the BNT162b2 vaccine and by therapeutic antibodies. Our results represent a systematic functional analysis of Omicron Spike adaptations that have allowed this SARS-CoV-2 variant to dominate the current pandemic.

| S-EPMC9289044 | biostudies-literature

Durability of Booster mRNA Vaccine against SARS-CoV-2 BA.2.12.1, BA.4, and BA.5 Subvariants.

Project description: Not available

| S-EPMC9511629 | biostudies-literature

SARS-CoV-2 hyperimmune intravenous human immunoglobulins neutralizes Omicron subvariants BA.1, BA.2, BA.2.12.1, BA.3 and BA.4/BA.5 for treatment of COVID-19.

Project description:Our study demonstrates that neither 2020-convalescent plasma (CP) nor 2019/2020-immunoglobulin (IVIG) neutralize Omicron subvariants BA.1 to BA.5. In contrast, hyperimmune 2020-hCoV-2IG lots neutralized Omicron VOCs, similar to 2022-CP from BA.1 breakthrough infections. Therefore, high-titer hCoV-2IG and CP could be evaluated for treatment of high-risk individuals infected with circulating Omicron subvariants.

| S-EPMC9384659 | biostudies-literature

Efficacy of Antibodies and Antiviral Drugs against Omicron BA.2.12.1, BA.4, and BA.5 Subvariants.

Project description: Not available

| S-EPMC9342381 | biostudies-literature