New research by scientists at the University of Kent, England, and the Goethe University Frankfurt, Germany, has shown that the Omicron variant is less effective than Delta at blocking a cellular defense mechanism against viruses, according to Science Daily.
The study found that Omicron causes less severe disease than Delta because it is less effective at inhibiting “interferon response,” a cellular defense mechanism against viruses.
In addition to that, cell culture findings have indicated that eight COVID-19 drugs and experimental therapies remain effective against Omicron.
The drugs include molnupiravir, ribavirin, remdesivir, favipravir, Paxlovid (nirmatrelvir and ritonavir), nafamostat, camostat, and aprotinin.
Although Omicron causes less severe disease than Delta, it is better at escaping immune protection by previous infections and vaccination.
The researchers explained that Omicron is particularly sensitive to inhibition by the interferon response, an unspecific immune response present in cells. This could be the reason why COVID-19 patients infected with Omicron are less likely to experience severe disease.
Study author Dr. Martin Michaelis of the University of Kent said, “Our study provides for the first time an explanation, why Omicron infections are less likely to cause severe disease. This is due to Omicron, in contrast to Delta, does not effectively inhibit the host cell interferon immune response.”
Dr. Jindrich Cinatl of the Institute of Medical Virology at the Goethe-University said, “Although cell culture experiments do not exactly reflect the more complex situation in a patient, our data provide encouraging evidence that the available antiviral COVID-19 drugs are also effective against Omicron.”
In another study conducted on nearly 70,000 COVID-19 positive people, researchers found that there is a substantially lower risk of hospitalizations and deaths from Omicron even after controlling for growing population immunity levels, suggesting that it is intrinsically less severe than Delta.
The study, conducted by the University of California, Berkeley, Kaiser Permanente, and the Centers for Disease Control and Prevention (CDC), found that people infected with Omicron were 50% less likely to be hospitalized, 75% less likely to need intensive care, and 90% less likely to die compared to those infected with Delta.
In addition, the researchers found that for Omicron, hospital stays lasted for about 1.5 days, but for Delta, they lasted for five days. Furthermore, nearly 90% of Omicron patients were discharged within two to three days.