Only 2 Antibody Therapeutics Effective Against Omicron... US Begins Emergency Stockpiling [Reading Science]

Reckonojoo is 'Completely Neutralized'

[Asia Economy Reporter Kim Bong-su] Among the COVID-19 antibody treatments developed worldwide, only two have been confirmed to be effective against the Omicron variant, and those countries have reportedly begun stockpiling them. South Korea's Regdanvimab (product name: Rekkiro-na-ju) was not included.

According to the international journal Nature on the 22nd, research by scientists from various countries on the Omicron variant, which has spread globally since last month, revealed that Omicron exhibits complete or partial resistance to all currently developed monoclonal antibody-based treatments.

Earlier, the Washington Post (WP) also reported similarly on the 17th, citing research from the University of Washington School of Medicine. According to the report, experiments conducted by the University of Washington medical research team on existing major antibody treatments showed that bamlanivimab and etesevimab developed by Eli Lilly in the U.S., casirivimab and imdevimab by Regeneron, and regdanvimab (product name Rekkiro-na-ju) by South Korea's Celltrion had completely lost their inhibitory effect against the Omicron variant. Additionally, tixagevimab and cilgavimab developed by AstraZeneca in the UK also showed reduced efficacy against Omicron.

On the other hand, sotrovimab, jointly developed by Vir Biotechnology in New York and GlaxoSmithKline (GSK), was confirmed to retain inhibitory effects against the Omicron variant. However, sotrovimab requires more than triple the dosage compared to other variants to achieve suppression against Omicron.

Accordingly, U.S. health authorities began stockpiling sotrovimab last week and plan to distribute it based on infection and hospitalization rates and Omicron prevalence by state. Stuart Turville, a researcher at Australia's Kirby Institute, told Nature, "Although the efficacy of sotrovimab against Omicron has significantly decreased, it differs from other antibody treatments," adding, "This is likely because sotrovimab targets a part of the spike protein that remains unchanged across many related coronaviruses."

[Image source=Yonhap News]

Furthermore, according to Nature, the antibody treatment DXP-604, jointly developed and under testing by China's BeiGene and Singlomics, was also confirmed to have inhibitory effects against the Omicron variant. Additionally, two antibody treatments developed by AstraZeneca, although their efficacy has considerably decreased, still retain some level of inhibitory effect.

Olivier Schwartz, a researcher at the Pasteur Institute in Paris, France, said, "When it was confirmed that Omicron's mutations were concentrated on the spike protein, I was afraid of what that would mean for monoclonal antibody treatments," adding, "The results are much worse than expected. We did not anticipate the antibody treatments would lose their effectiveness to this extent."

However, these experimental results had been somewhat anticipated among scientists. Monoclonal antibody-based treatments work by binding to the virus's spike protein to neutralize it and prevent infection of human cells. Since Omicron has many mutations in the spike protein, it was predicted that antibodies might not recognize it.

Nature reported, "If antibody treatments become ineffective, healthcare workers will lose a critical tool to prevent severe illness," warning, "If Omicron turns out to be a variant causing serious harm, it could be disastrous."

Consequently, attention is shifting to oral antiviral drugs instead of antibody treatments. These drugs are cheaper and have different mechanisms of action, so they are expected to be effective against the Omicron variant. Antiviral drugs inhibit the early stages of viral replication by suppressing viral attachment and entry. In this regard, multinational pharmaceutical company Pfizer announced on the 14th that its antiviral drug Paxlovid, administered to high-risk patients hospitalized immediately after COVID-19 symptom onset, showed an 89% reduction in hospitalization and death.

Additionally, the ability of medical personnel to quickly distinguish between Delta and Omicron variants during COVID-19 testing is emerging as a challenge in frontline medical settings. If healthcare workers have testing tools to differentiate between Delta and Omicron variants, they can select appropriate treatments. Without such tools, treatment may be delayed, increasing fatality rates, and decisions about Omicron presence must rely solely on regional spread data.

This content was produced with the assistance of AI translation services.