A recently published study has found that all three Omicron subvariants affect the efficacies of current vaccines and antibody treatments.
Since its discovery in November of last year, the Omicron variant has led to a huge surge in cases across the world. Not only has it become the dominant strain worldwide, but also caused countries to re-impose lockdown measures. The emergence of Omicron has further revealed the rise in two subvariants: BA.1.1 and BA.2. Although BA.2, also called stealth Omicron, was once the dominant strain, it has now been replaced by BA.1.1. Currently, BA.1.1 accounts for approximately 40% of all global Omicron cases. Due to the varying number of genetic mutations within the spike protein of all three subvariants, researchers continue to closely monitor their spread.
Recently, researchers at the University of Hong Kong and Columbia University investigated the antibody-escaping ability of all three Omicron subvariants. They tested blood samples from individuals who had either received either of the two mRNA vaccines or were infected by the wild-type SARS-CoV-2. Results revealed decreased activity against both BA.1.1 and BA.2. However, samples from individuals who had received three mRNA shots demonstrated a lower decline in neutralization. Thus, revealing the importance of booster shots in enhancing immunity.
The researchers further tested the efficacy of 19 monoclonal antibodies. According to the results, 17 out of 19 antibodies demonstrated ineffectiveness against the BA.2 subvariant. However, the newly authorized monoclonal antibody, bebtelovimab, could effectively treat all three Omicron subvariants.
The study authors suggest that as new variants continue to emerge, researchers should carry on working on more effective therapeutic options.
Sho Iketani et al, Antibody evasion properties of SARS-CoV-2 Omicron sublineages, Nature (2022). DOI: 10.1038/s41586-022-04594-4