'1 Million Daily' US Omicron Variant Surge Due to This? [Reading Science]

Research Shows Over Half of Infected Individuals Remain Contagious After 5 Days
Exceeding Self-Isolation Period Set by US CDC

[Asia Economy Reporter Kim Bong-su] It has been pointed out that the rapid spread of the COVID-19 Omicron variant in the United States and other countries may have been partly due to excessively lenient isolation policies for infected individuals. This is because a study found that although the self-isolation period for infected individuals was set at 5 days, about half of them still retained the ability to transmit the virus after that period.

According to the international academic journal Nature on the 21st, a research team from Harvard Medical School recently investigated COVID-19 infected individuals and found that those infected with the Delta variant were measured to release more virus than those infected with the Omicron variant. A research team from the University of Geneva in Switzerland also tested the viral load of 150 infected patients and discovered that there was little difference in viral load between the Delta and Omicron variants. Considering that, in general, the strong transmissibility of coronaviruses is proportional to the viral load released by patients, this is a completely opposite result. This is because the Omicron variant has been confirmed to have more than three times the transmissibility of the Delta variant.

The research team particularly found that about half of the people who were vaccinated but experienced breakthrough infections with the Delta variant, as well as those infected with Omicron, were still releasing virus at levels capable of spreading infection even 5 days after confirmation. Nature pointed out that these research results provide many implications for the isolation policies of governments worldwide regarding COVID-19 infected individuals. For example, the U.S. Centers for Disease Control and Prevention (CDC) implements guidelines to isolate for 5 days after confirmation or symptom onset. Additionally, no further testing is conducted upon ending isolation, and only mask-wearing for 5 days is recommended.

Jonathan Grad, a professor of infectious diseases at Harvard T.H. Chan School of Public Health, stated, "This research result is concerning," adding, "The Omicron variant has made public health decision-making more difficult. The Omicron variant also shows greater individual variation in viral load than the Delta variant, making it difficult to establish clear standards."

Meanwhile, the number of COVID-19 infections in the United States rapidly increased since last month when the Omicron variant spread, surpassing an average of 1 million cases per day in early this month. Since then, the recent spread has slowed, reducing the number to around 800,000 cases per day.