Omicron lineage continues to evolve, producing subvariants that are not only more transmissible but also more evasive to antibodies. Novel Omicron subvariant BA.2.12.1 is only modestly (1.8-fold) more resistant to sera from vaccinated and boosted individuals, whereas BA.4/5 is substantially (4.2-fold) more resistant and thus more likely to lead to vaccine breakthrough infections.
Contents
SARS-CoV-2 Omicron BA.2.12.1, BA.4, and BA.5 subvariants evolved to extend antibody evasion
Omicron lineage continues to evolve, producing subvariants that are not only more transmissible but also more evasive to antibodies. Novel Omicron subvariant BA.2.12.1 is only modestly (1.8-fold) more resistant to sera from vaccinated and boosted individuals, whereas BA.4/5 is substantially (4.2-fold) more resistant and thus more likely to lead to vaccine breakthrough infections. Among therapeutic antibodies authorized for clinical use, only bebtelovimab (LY-COV1404) retains full potency against both BA.2.12.1 and BA.4/5. Read the full article here.
In summary: Omicron subvariants can be more transmissible and more evasive to antibodies
Rapid evaluation of COVID-19 vaccine effectiveness against symptomatic infection with SARS-CoV-2 variants by analysis of genetic distance
Genetic distance* (GD) of the receptor-binding domain of the SARS-CoV-2 spike protein is highly predictive of vaccine protection. The authors applied the model to predict protection mediated by existing vaccines against new genetic variants and validated the results by published real-world and clinical trial data. The model showed high concordance of predicted vaccine efficacy (VE) with observed VE. The VE-GD framework enables predictions of vaccine protection in real-time and offers a rapid evaluation method against novel variants that may inform vaccine deployment and public health responses. Read the full article here.
*Genetic distance is a measure of the genetic divergence between species or between populations within a species. Populations with many similar alleles have small genetic distances.
In summary: A modeling framework could predict vaccine efficacy against novel variants and guide vaccine deployment and public health responses in the future
References
[1] Wang et al. Antibody evasion by SARS-CoV-2 Omicron subvariants BA.2.12.1, BA.4, and BA.5. preprint bioRxiv (2022). https://www.biorxiv.org/content/10.1101/2022.05.26.493517v2
[2] Cao L et al. Rapid evaluation of COVID-19 vaccine effectiveness against symptomatic infection with SARS-CoV-2 variants by analysis of genetic distance. Nat Med (2022). https://doi.org/10.1038/s41591-022-01877-1
