Omicron stays unhindered by most antibody treatments, show early tests
Amid an explosive surge of Covid-19 cases around the world majorly caused by the highly transmissible Omicron variant, studies show that antibody treatments that were effective against the previous coronavirus strains may not be effective against the new variant.
According to a report by Nature journal, several pre-print publications tell that Omicron is “totally or partially resistant to all currently available treatments based on these monoclonal antibodies”. As a result, many manufacturers of antibody therapy have already conceded their products due to a much lower potency against Omicron, as compared to other variants.
The only two antibodies that show strong evidence, the report stated, were sotrovimab, developed by Vir Biotechnology in San Francisco, California, and GSK, headquartered in London; and DXP-604.
The US health officials said that they will ration sotrovimab to various states depending on the Covid-19 severity and number of infections and hospitalisations. However, many countries have no access to sotrovimab at all.
Generally, monoclonal-antibody treatments for Covid-19, whether from a single antibody or a cocktail of several, prevent the virus from infecting human cells, reducing the risk of the viral infection by up to 85 per cent.
In the case of Omicron, the concentration of the treatment which should cut viral replication in half, could not even reach the threshold, even with increased concentration, researchers quoted in the report said.
“We didn’t expect to see such a shift in the antibodies’ effectiveness,” said Olivier Schwartz, a virologist at the Pasteur Institute in Paris and a co-author of one of the pre-prints.
Sotrovimab is the best available antibody treatment. But the only two antibody treatments that retain some neutralisation power against Omicron are the ones developed by AstraZeneca in Cambridge, United Kingdom, studies found.
So far, Omicron has proved to be more contagious but less severe as compared to the highly infectious Delta strain. Although there are fewer hospitalisations from the new variant till now, “if Omicron bites hard, it’ll be a recipe for disaster,” said Stuart Turville, a virologist at the Kirby Institute in Sydney, Australia, and a co-author of one of the preprints.
Omicron is the dominant variant in the US. New Covid-19 cases per day have more than tripled over the past two weeks, reaching a record-shattering average of 480,000. Schools, hospitals and airlines in the US are struggling as scores of infected workers went into isolation.