According to new research from Columbia University and the University of Hong Kong, only one existing approved antibody therapy retains its activity against all omicron subvariants. The study also demonstrates that the efficacy of mRNA vaccinations against all three omicron subvariants is lower.
David D. Ho, MD, director of the Aaron Diamond AIDS Research Center and the Clyde ’56 and Helen Wu Professor of Medicine at Columbia University Vagelos College of Physicians and Surgeons, published the findings in Nature on March 3.
Omicron is a highly transmissible strain of SARS-CoV-2 that has caused the greatest increase in COVID infections in numerous countries so far. BA.1, BA.1.1, and BA.2 are the names given to three subvariants of Omicron that share 21 mutations in the spike protein.
Omicron was discovered in November 2021, with BA.1 being the most common variant at the time.BA.1 instances have decreased since December, but BA.1.1 cases have increased and currently account for almost 40% of all omicron cases sequenced globally. The BA.2 subvariant now accounts for only 10% of all omicron instances worldwide, but its prevalence is increasing.Ho
and his colleagues investigated the effectiveness of 19 monoclonal antibodies and sera from people inoculated with one of two current mRNA vaccines to neutralize the three known subvariants of omicron.
In blood samples from people who had received two mRNA shots, the researchers detected a similar decrease in neutralization activity against BA.1.1 and BA.2. This was consistent with their prior investigation into the BA.1 variation. The drop in neutralization was less pronounced in blood samples from people who had had three mRNA doses, highlighting the need for booster shots in maintaining immunity.
In neutralization tests, all three genotypes demonstrated high resistance to the majority of monoclonal antibodies tested. 17 of the 19 antibodies tested negative for the BA.2 subvariant. The researchers discovered that bebtelovimab, the most recent monoclonal antibody to get FDA Emergency Use Authorization, is the only antibody therapy now available that can adequately cure all three omicron subvariants.
“The emergence of new variants is narrowing our treatment options and challenging the effectiveness of our current vaccines. It is critical that we don’t relax prematurely and continue to devise novel strategies to contain this ever-evolving pathogen.”says Ho.
“The advent of novel variations is limiting our therapeutic options and calling into question the efficacy of our current vaccinations,” adds Ho. It’s vital that we don’t become too comfortable and keep coming up with new ways to combat this ever-evolving infection.
The research, “Antibody evasion properties of SARS-CoV-2 Omicron sublineages,” was published in Nature on March 3.